fbpx
Wikipedia

Brown dwarf

January 29, 2023

Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen (1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most massive gas giant planets and the least massive stars, approximately 13 to 80 times that of Jupiter (MJ).[2][3] However, they can fuse deuterium (2H) and the most massive ones (> 65 MJ) can fuse lithium (7Li).[3]

Artist's concept of a T-type brown dwarf
Comparison: most brown dwarfs are slightly larger than Jupiter (15–20%),[1] but are still up to 80 times more massive due to greater density. Image is to scale, with Jupiter's radius being 10 times that of Earth, and the Sun's radius is 10 times that of Jupiter.

Astronomers classify self-luminous objects by spectral class, a distinction intimately tied to the surface temperature, and brown dwarfs occupy types M, L, T, and Y.[4][5] As brown dwarfs do not undergo stable hydrogen fusion, they cool down over time, progressively passing through later spectral types as they age.

Despite their name, to the naked eye, brown dwarfs would appear in different colors depending on their temperature.[4] The warmest ones are possibly orange or red,[6] while cooler brown dwarfs would likely appear magenta or black to the human eye.[4][7] Brown dwarfs may be fully convective, with no layers or chemical differentiation by depth.[8]

Though their existence was initially theorized in the 1960s, it was not until the mid-1990s that the first unambiguous brown dwarfs were discovered. As brown dwarfs have relatively low surface temperatures, they are not very bright at visible wavelengths, emitting most of their light in the infrared. However, with the advent of more capable infrared detecting devices, thousands of brown dwarfs have been identified. The nearest-known brown dwarfs are located in the Luhman 16 system, a binary of L- and T-type brown dwarfs about 6.5 light-years (2.0 parsecs) away from the Sun. Luhman 16 is the third closest system to the Sun after Alpha Centauri and Barnard's Star.

History

 
The smaller object is Gliese 229B, about 20 to 50 times the mass of Jupiter, orbiting the star Gliese 229. It is in the constellation Lepus, about 19 light-years from Earth.

Early theorizing

 
Planets, brown dwarfs, stars (not to scale)

The objects now called "brown dwarfs" were theorized by Shiv S. Kumar in the 1960s to exist and were originally called black dwarfs,[9] a classification for dark substellar objects floating freely in space that were not massive enough to sustain hydrogen fusion. However, (a) the term black dwarf was already in use to refer to a cold white dwarf; (b) red dwarfs fuse hydrogen; and (c) these objects may be luminous at visible wavelengths early in their lives. Because of this, alternative names for these objects were proposed, including planetar and substar. In 1975, Jill Tarter suggested the term "brown dwarf", using "brown" as an approximate color.[6][10][11]

The term "black dwarf" still refers to a white dwarf that has cooled to the point that it no longer emits significant amounts of light. However, the time required for even the lowest-mass white dwarf to cool to this temperature is calculated to be longer than the current age of the universe; hence such objects are expected to not yet exist.[12]

Early theories concerning the nature of the lowest-mass stars and the hydrogen-burning limit suggested that a population I object with a mass less than 0.07 solar masses (M☉) or a population II object less than 0.09 M☉ would never go through normal stellar evolution and would become a completely degenerate star.[13] The first self-consistent calculation of the hydrogen-burning minimum mass confirmed a value between 0.07 and 0.08 solar masses for population I objects.[14][15]

Deuterium fusion

The discovery of deuterium burning down to 0.013 M☉ (13.6 jupiter mass) and the impact of dust formation in the cool outer atmospheres of brown dwarfs in the late 1980s brought these theories into question. However, such objects were hard to find because they emit almost no visible light. Their strongest emissions are in the infrared (IR) spectrum, and ground-based IR detectors were too imprecise at that time to readily identify any brown dwarfs.

Since then, numerous searches by various methods have sought these objects. These methods included multi-color imaging surveys around field stars, imaging surveys for faint companions of main-sequence dwarfs and white dwarfs, surveys of young star clusters, and radial velocity monitoring for close companions.

GD 165B and class L

For many years, efforts to discover brown dwarfs were fruitless. In 1988, however, a faint companion to the white dwarf star GD 165 was found in an infrared search of white dwarfs. The spectrum of the companion GD 165B was very red and enigmatic, showing none of the features expected of a low-mass red dwarf. It became clear that GD 165B would need to be classified as a much cooler object than the latest M dwarfs then known. GD 165B remained unique for almost a decade until the advent of the Two Micron All-Sky Survey (2MASS) which discovered many objects with similar colors and spectral features.

Today, GD 165B is recognized as the prototype of a class of objects now called "L dwarfs".[16][17]

Although the discovery of the coolest dwarf was highly significant at the time, it was debated whether GD 165B would be classified as a brown dwarf or simply a very-low-mass star, because observationally it is very difficult to distinguish between the two.[citation needed]

Soon after the discovery of GD 165B, other brown-dwarf candidates were reported. Most failed to live up to their candidacy, however, because the absence of lithium showed them to be stellar objects. True stars burn their lithium within a little over 100 Myr, whereas brown dwarfs (which can, confusingly, have temperatures and luminosities similar to true stars) will not. Hence, the detection of lithium in the atmosphere of an object older than 100 Myr ensures that it is a brown dwarf.

Gliese 229B and class T

The first class "T" brown dwarf was discovered in 1994 by Caltech astronomers Shrinivas Kulkarni, Tadashi Nakajima, Keith Matthews and Rebecca Oppenheimer,[18] and Johns Hopkins scientists Samuel T. Durrance and David Golimowski. It was confirmed in 1995 as a substellar companion to Gliese 229. Gliese 229b is one of the first two instances of clear evidence for a brown dwarf, along with Teide 1. Confirmed in 1995, both were identified by the presence of the 670.8 nm lithium line. The latter was found to have a temperature and luminosity well below the stellar range.

Its near-infrared spectrum clearly exhibited a methane absorption band at 2 micrometres, a feature that had previously only been observed in the atmospheres of giant planets and that of Saturn's moon Titan. Methane absorption is not expected at any temperature of a main-sequence star. This discovery helped to establish yet another spectral class even cooler than L dwarfs, known as "T dwarfs", for which Gliese 229B is the prototype.

Teide 1 and class M

The first confirmed class "M" brown dwarf was discovered by Spanish astrophysicists Rafael Rebolo (head of team), María Rosa Zapatero-Osorio, and Eduardo L. Martín in 1994.[19] This object, found in the Pleiades open cluster, received the name Teide 1. The discovery article was submitted to Nature in May 1995, and published on 14 September 1995.[20][21] Nature highlighted "Brown dwarfs discovered, official" in the front page of that issue.

Teide 1 was discovered in images collected by the IAC team on 6 January 1994 using the 80 cm telescope (IAC 80) at Teide Observatory and its spectrum was first recorded in December 1994 using the 4.2 m William Herschel Telescope at Roque de los Muchachos Observatory (La Palma). The distance, chemical composition, and age of Teide 1 could be established because of its membership in the young Pleiades star cluster. Using the most advanced stellar and substellar evolution models at that moment, the team estimated for Teide 1 a mass of 55 ± 15 MJ,[22] which is below the stellar-mass limit. The object became a reference in subsequent young brown dwarf related works.

In theory, a brown dwarf below 65 MJ is unable to burn lithium by thermonuclear fusion at any time during its evolution. This fact is one of the lithium test principles used to judge the substellar nature of low-luminosity and low-surface-temperature astronomical bodies.

High-quality spectral data acquired by the Keck 1 telescope in November 1995 showed that Teide 1 still had the initial lithium abundance of the original molecular cloud from which Pleiades stars formed, proving the lack of thermonuclear fusion in its core. These observations confirmed that Teide 1 is a brown dwarf, as well as the efficiency of the spectroscopic lithium test.

For some time, Teide 1 was the smallest-known object outside the Solar System that had been identified by direct observation. Since then, over 1,800 brown dwarfs have been identified,[23] even some very close to Earth like Epsilon Indi Ba and Bb, a pair of brown dwarfs gravitationally bound to a Sun-like star 12 light-years from the Sun,[24] and Luhman 16, a binary system of brown dwarfs at 6.5 light-years from the Sun.

Theory

The standard mechanism for star birth is through the gravitational collapse of a cold interstellar cloud of gas and dust. As the cloud contracts it heats due to the Kelvin–Helmholtz mechanism. Early in the process the contracting gas quickly radiates away much of the energy, allowing the collapse to continue. Eventually, the central region becomes sufficiently dense to trap radiation. Consequently, the central temperature and density of the collapsed cloud increases dramatically with time, slowing the contraction, until the conditions are hot and dense enough for thermonuclear reactions to occur in the core of the protostar. For most stars, gas and radiation pressure generated by the thermonuclear fusion reactions within the core of the star will support it against any further gravitational contraction. Hydrostatic equilibrium is reached and the star will spend most of its lifetime fusing hydrogen into helium as a main-sequence star.

If, however, the initial[25] mass of the protostar is less than about 0.08 M☉,[26] normal hydrogen thermonuclear fusion reactions will not ignite in the core. Gravitational contraction does not heat the small protostar very effectively, and before the temperature in the core can increase enough to trigger fusion, the density reaches the point where electrons become closely packed enough to create quantum electron degeneracy pressure. According to the brown dwarf interior models, typical conditions in the core for density, temperature and pressure are expected to be the following:

  •  
  •  
  •  

This means that the protostar is not massive enough and not dense enough to ever reach the conditions needed to sustain hydrogen fusion. The infalling matter is prevented, by electron degeneracy pressure, from reaching the densities and pressures needed.

Further gravitational contraction is prevented and the result is a "failed star", or brown dwarf that simply cools off by radiating away its internal thermal energy. Note that, in principle, it is possible for a brown dwarf to slowly accrete mass above the hydrogen burning limit without initiating hydrogen fusion. This could happen via mass transfer in a binary brown dwarf system.[25]

High-mass brown dwarfs versus low-mass stars

Lithium is generally present in brown dwarfs and not in low-mass stars. Stars, which reach the high temperature necessary for fusing hydrogen, rapidly deplete their lithium. Fusion of lithium-7 and a proton occurs producing two helium-4 nuclei. The temperature necessary for this reaction is just below that necessary for hydrogen fusion. Convection in low-mass stars ensures that lithium in the whole volume of the star is eventually depleted. Therefore, the presence of the lithium spectral line in a candidate brown dwarf is a strong indicator that it is indeed a substellar object.

The lithium test

The use of lithium to distinguish candidate brown dwarfs from low-mass stars is commonly referred to as the lithium test, and was pioneered by Rafael Rebolo, Eduardo Martín and Antonio Magazzu. However, lithium is also seen in very young stars, which have not yet had enough time to burn it all.

Heavier stars, like the Sun, can also retain lithium in their outer layers, which never get hot enough to fuse lithium, and whose convective layer does not mix with the core where the lithium would be rapidly depleted. Those larger stars are easily distinguishable from brown dwarfs by their size and luminosity.

Conversely, brown dwarfs at the high end of their mass range can be hot enough to deplete their lithium when they are young. Dwarfs of mass greater than 65 MJ can burn their lithium by the time they are half a billion years old,[27] thus the lithium test is not perfect.

Atmospheric methane

Unlike stars, older brown dwarfs are sometimes cool enough that, over very long periods of time, their atmospheres can gather observable quantities of methane which cannot form in hotter objects. Dwarfs confirmed in this fashion include Gliese 229B.

Iron rain

Main-sequence stars cool, but eventually reach a minimum bolometric luminosity that they can sustain through steady fusion. This varies from star to star, but is generally at least 0.01% that of the Sun.[citation needed] Brown dwarfs cool and darken steadily over their lifetimes; sufficiently old brown dwarfs will be too faint to be detectable.

Iron rain as part of atmospheric convection processes is possible only in brown dwarfs, and not in small stars. The spectroscopy research into iron rain is still ongoing, but not all brown dwarfs will always have this atmospheric anomaly. In 2013, a heterogeneous iron-containing atmosphere was imaged around the B component in the nearby Luhman 16 system.[28]

Low-mass brown dwarfs versus high-mass planets

 
An artistic concept of the brown dwarf around the star HD 29587, a companion known as HD 29587 b, and estimated to be about 55 Jupiter masses

Like stars, brown dwarfs form independently, but, unlike stars, lack sufficient mass to "ignite". Like all stars, they can occur singly or in close proximity to other stars. Some orbit stars and can, like planets, have eccentric orbits.

Size and fuel-burning ambiguities

Brown dwarfs are all roughly the same radius as Jupiter. At the high end of their mass range (60–90 MJ), the volume of a brown dwarf is governed primarily by electron-degeneracy pressure,[29] as it is in white dwarfs; at the low end of the range (10 MJ), their volume is governed primarily by Coulomb pressure, as it is in planets. The net result is that the radii of brown dwarfs vary by only 10–15% over the range of possible masses. Moreover, the mass–radius relationship shows no change from about one Saturn mass to the onset of hydrogen burning (0.080±0.008 M☉), suggesting that from this perspective brown dwarfs are simply high-mass Jovian planets.[30] This can make distinguishing them from planets difficult.

In addition, many brown dwarfs undergo no fusion; even those at the high end of the mass range (over 60 MJ) cool quickly enough that after 10 million years they no longer undergo fusion.

Heat spectrum

X-ray and infrared spectra are telltale signs of brown dwarfs. Some emit X-rays; and all "warm" dwarfs continue to glow tellingly in the red and infrared spectra until they cool to planet-like temperatures (under 1,000 K).

Gas giants have some of the characteristics of brown dwarfs. Like the Sun, Jupiter and Saturn are both made primarily of hydrogen and helium. Saturn is nearly as large as Jupiter, despite having only 30% the mass. Three of the giant planets in the Solar System (Jupiter, Saturn, and Neptune) emit much more (up to about twice) heat than they receive from the Sun.[31][32] All four giant planets have their own "planetary" systems, in the form of extensive moon systems.

Current IAU standard

Currently, the International Astronomical Union considers an object above 13 MJ (the limiting mass for thermonuclear fusion of deuterium) to be a brown dwarf, whereas an object under that mass (and orbiting a star or stellar remnant) is considered a planet. The minimum mass required to trigger sustained hydrogen-burning (about 80 MJ) forms the upper limit of the definition.[3][33]

It is also debated whether brown dwarfs would be better defined by their formation process rather than by theoretical mass limits based on nuclear fusion reactions.[4] Under this interpretation brown dwarfs are those objects that represent the lowest-mass products of the star formation process, while planets are objects formed in an accretion disk surrounding a star. The coolest free-floating objects discovered such as WISE 0855, as well as the lowest-mass young objects known like PSO J318.5−22, are thought to have masses below 13 MJ, and as a result are sometimes referred to as planetary mass objects due to the ambiguity of whether they should be regarded as rogue planets or brown dwarfs. There are planetary mass objects known to orbit brown dwarfs, such as 2M1207b, MOA-2007-BLG-192Lb, 2MASS J044144b and Oph 98 B.

The 13 Jupiter-mass cutoff is a rule of thumb rather than something of precise physical significance. Larger objects will burn most of their deuterium and smaller ones will burn only a little, and the 13 Jupiter-mass value is somewhere in between.[34] The amount of deuterium burnt also depends to some extent on the composition of the object, specifically on the amount of helium and deuterium present and on the fraction of heavier elements, which determines the atmospheric opacity and thus the radiative cooling rate.[35]

As of 2011 the Extrasolar Planets Encyclopaedia included objects up to 25 Jupiter masses, saying, "The fact that there is no special feature around 13 MJup in the observed mass spectrum reinforces the choice to forget this mass limit".[36] As of 2016, this limit was increased to 60 Jupiter masses,[37] based on a study of mass–density relationships.[38]

The Exoplanet Data Explorer includes objects up to 24 Jupiter masses with the advisory: "The 13 Jupiter-mass distinction by the IAU Working Group is physically unmotivated for planets with rocky cores, and observationally problematic due to the sin i ambiguity."[39] The NASA Exoplanet Archive includes objects with a mass (or minimum mass) equal to or less than 30 Jupiter masses.[40]

Sub-brown dwarf

Main article: Sub-brown dwarf
 
A size comparison between the Sun, a young sub-brown dwarf, and Jupiter. As the sub-brown dwarf ages, it will gradually cool and shrink.

Objects below 13 MJ, called sub-brown dwarf or planetary-mass brown dwarf, form in the same manner as stars and brown dwarfs (i.e. through the collapse of a gas cloud) but have a mass below the limiting mass for thermonuclear fusion of deuterium.[41]

Some researchers call them free-floating planets,[42] whereas others call them planetary-mass brown dwarfs.[43]

Role of other physical properties in the mass estimate

While spectroscopic features can help to distinguish between low mass stars and brown dwarfs, it is often necessary to estimate the mass to come to a conclusion. The theory behind the mass estimate is that brown dwarfs with a similar mass form in a similar way and are hot when they form. Some have spectral types that are similar to low-mass stars, such as 2M1101AB. As they cool down the brown dwarfs should retain a range of luminosities depending on the mass.[44] Without the age and luminosity a mass estimate is difficult; for example, an L-type brown dwarf could be an old brown dwarf with a high mass (possibly a low-mass star) or a young brown dwarf with a very low mass. For Y dwarfs this is less of a problem as they remain low-mass objects near the sub-brown dwarf limit, even for relative high age estimates.[45] For L and T dwarfs it is still useful to have an accurate age estimate. The luminosity is here the less concerning property, as this can be estimated from the spectral energy distribution.[46] The age estimate can be done in two ways. Either the brown dwarf is young and still has spectral features that are associated with youth or the brown dwarf co-moves with a star or stellar group (star cluster or association), which have easier to obtain age estimates. A very young brown dwarf that was further studied with this method is 2M1207 and the companion 2M1207b. Based on the location, proper motion and spectral signature, this object was determined to belong to the ~8 million year old TW Hydrae association and the mass of the secondary was determined to be below the deuterium burning limit with 8 ± 2 MJ.[47] A very old example of an age estimate that makes use of co-movement is the brown dwarf + white dwarf binary COCONUTS-1, with the white dwarf having a total age of 7.3+2.8
−1.6 billion years. In this case the mass was not estimated with the derived age, but the co-movement provided an accurate distance estimate, using Gaia parallax. Using this measurement the authors estimated the radius, which was then used to estimate the mass for the brown dwarf as 15.4+0.9
−0.8 MJ.[48]

Observations

Classification of brown dwarfs

Spectral class M

 
Artist's vision of a late-M dwarf

These are brown dwarfs with a spectral class of M5.5 or later; they are also called late-M dwarfs. These can be considered red dwarfs in the eyes of some scientists.[citation needed] Many brown dwarfs with spectral type M are young objects, such as Teide 1.

Spectral class L

 
Artist's vision of an L dwarf

The defining characteristic of spectral class M, the coolest type in the long-standing classical stellar sequence, is an optical spectrum dominated by absorption bands of titanium(II) oxide (TiO) and vanadium(II) oxide (VO) molecules. However, GD 165B, the cool companion to the white dwarf GD 165, had none of the hallmark TiO features of M dwarfs. The subsequent identification of many objects like GD 165B ultimately led to the definition of a new spectral class, the L dwarfs, defined in the red optical region of the spectrum not by metal-oxide absorption bands (TiO, VO), but by metal hydride emission bands (FeH, CrH, MgH, CaH) and prominent atomic lines of alkali metals (Na, K, Rb, Cs). As of 2013, over 900 L dwarfs have been identified,[23] most by wide-field surveys: the Two Micron All Sky Survey (2MASS), the Deep Near Infrared Survey of the Southern Sky (DENIS), and the Sloan Digital Sky Survey (SDSS). This spectral class contains not only the brown dwarfs, because the coolest main-sequence stars above brown dwarfs (> 80 MJ) have the spectral class L2 to L6.[49]

Spectral class T

 
Artist's vision of a T dwarf

As GD 165B is the prototype of the L dwarfs, Gliese 229B is the prototype of a second new spectral class, the T dwarfs. T dwarfs are pinkish-magenta. Whereas near-infrared (NIR) spectra of L dwarfs show strong absorption bands of H2O and carbon monoxide (CO), the NIR spectrum of Gliese 229B is dominated by absorption bands from methane (CH4), features that were found only in the giant planets of the Solar System and Titan. CH4, H2O, and molecular hydrogen (H2) collision-induced absorption (CIA) give Gliese 229B blue near-infrared colors. Its steeply sloped red optical spectrum also lacks the FeH and CrH bands that characterize L dwarfs and instead is influenced by exceptionally broad absorption features from the alkali metals Na and K. These differences led J. Davy Kirkpatrick to propose the T spectral class for objects exhibiting H- and K-band CH4 absorption. As of 2013, 355 T dwarfs are known.[23] NIR classification schemes for T dwarfs have recently been developed by Adam Burgasser and Tom Geballe. Theory suggests that L dwarfs are a mixture of very-low-mass stars and sub-stellar objects (brown dwarfs), whereas the T dwarf class is composed entirely of brown dwarfs. Because of the absorption of sodium and potassium in the green part of the spectrum of T dwarfs, the actual appearance of T dwarfs to human visual perception is estimated to be not brown, but magenta.[50][51] T-class brown dwarfs, such as WISE 0316+4307, have been detected more than 100 light-years from the Sun.

Spectral class Y

 
Artist's vision of a Y dwarf

In 2009, the coolest-known brown dwarfs had estimated effective temperatures between 500 and 600 K (227–327 °C; 440–620 °F), and have been assigned the spectral class T9. Three examples are the brown dwarfs CFBDS J005910.90–011401.3, ULAS J133553.45+113005.2 and ULAS J003402.77−005206.7.[52] The spectra of these objects have absorption peaks around 1.55 micrometres.[52] Delorme et al. have suggested that this feature is due to absorption from ammonia and that this should be taken as indicating the T–Y transition, making these objects of type Y0.[52][53] However, the feature is difficult to distinguish from absorption by water and methane,[52] and other authors have stated that the assignment of class Y0 is premature.[54]

In April 2010, two newly discovered ultracool sub-brown dwarfs (UGPS 0722-05 and SDWFS 1433+35) were proposed as prototypes for spectral class Y0.[55]

In February 2011, Luhman et al. reported the discovery of WD 0806-661B, a brown dwarf companion to a nearby white dwarf with a temperature of c. 300 K (27 °C; 80 °F) and mass of 7 MJ.[56] Though of planetary mass, Rodriguez et al. suggest it is unlikely to have formed in the same manner as planets.[57]

Shortly after that, Liu et al. published an account of a "very cold" (c. 370 K (97 °C; 206 °F)) brown dwarf orbiting another very-low-mass brown dwarf and noted that "Given its low luminosity, atypical colors and cold temperature, CFBDS J1458+10B is a promising candidate for the hypothesized Y spectral class."[58]

In August 2011, scientists using data from NASA's Wide-field Infrared Survey Explorer (WISE) discovered six objects that they classified as Y dwarfs with temperatures as cool as 25 °C (298 K; 77 °F).[59][60]

 
WISE 0458+6434 is the first ultra-cool brown dwarf (green dot) discovered by WISE. The green and blue comes from infrared wavelengths mapped to visible colors.

WISE data has revealed hundreds of new brown dwarfs. Of these, fourteen are classified as cool Ys.[23] One of the Y dwarfs, called WISE 1828+2650, was, as of August 2011, the record holder for the coldest brown dwarf—emitting no visible light at all, this type of object resembles free-floating planets more than stars. WISE 1828+2650 was initially estimated to have an atmospheric temperature cooler than 300 K (27 °C; 80 °F).[61] Its temperature has since been revised and newer estimates put it in the range of 250 to 400 K (−23 to 127 °C; −10 to 260 °F).[62]

In April 2014, WISE 0855−0714 was announced with a temperature profile estimated around 225 to 260 K (−48 – −13 °C; −55–8 °F) and a mass of 3 to 10 MJ.[63] It was also unusual in that its observed parallax meant a distance close to 7.2 ± 0.7 light-years from the Solar System.

The CatWISE catalog combines NASA's WISE and NEOWISE survey.[64] It expands the number of faint sources and is therefore used to find the faintest brown dwarfs, including Y dwarfs. Seventeen candidate Y dwarfs were discovered by the CatWISE researchers. Initial color with the Spitzer Space Telescope indicated that CW1446 is one of the reddest and coldest Y dwarfs.[65] Additional data with Spitzer showed that CW1446 is the fifth reddest brown dwarf with a temperature of about 310 to 360 K (37–87 °C; 98–188 °F) at a distance of about 10 parsec.[45]

A search of the CatWISE catalog in 2019 revealed CWISEP J1935-1546, one of the coldest brown dwarfs with an estimated temperature of 270 to 360 K (−3–87 °C; 26–188 °F).[66]

In January 2020 the discovery of WISE J0830+2837, initially discovered by citizen scientists of the Backyard Worlds project, was presented at the 235th meeting of the American Astronomical Society. This Y dwarf is 36.5 light-years distant from the Solar System and has a temperature of about 350 K (77 °C; 170 °F).[67]

Role of vertical mixing

 
Major chemical pathways linking carbon monoxide and methane.The short-lived radicals are marked with a dot. Adopted from Zahnle & Marley[68]

In the hydrogen-dominated atmosphere of brown dwarfs a chemical equilibrium between carbon monoxide and methane exists. Carbon monoxide reacts with hydrogen molecules and forms methane and hydroxy in this reaction. The hydroxy radical might later react with hydrogen and form water molecules. In the other direction of the reaction methane reacts with hydroxy and forms carbon monoxide and hydrogen. The chemical reaction is tilted towards carbon monoxide at higher temperatures (L-dwarfs) and lower pressure. At lower temperatures (T-dwarfs) and higher pressure the reaction is tilted towards methane and methane predominates at the T/Y-boundary. Vertical mixing of the atmosphere can however cause methane to sink into lower layers of the atmosphere and carbon monoxide to rise from these lower and hotter layers. The carbon monoxide is slow to react back into methane because of an energy barrier that prevents the break down of the C-O bonds. This forces the observable atmosphere of a brown dwarf to be in a chemical disequilibrium. The L/T transition is mainly defined with the transition from a carbon monoxide dominated atmosphere in L-dwarfs to a methane dominated atmosphere in T-dwarfs. The amount of vertical mixing can therefore push the L/T-transition to lower or higher temperatures. This becomes important for objects with modest surface gravity and extended atmospheres, such as giant exoplanets. This pushes the L/T transition to lower temperatures for giant exoplanets. For brown dwarfs this transition occurs at around 1200 K. The exoplanet HR 8799c on the other hand does not show any methane, while having a temperature of 1100K.[68]

The transition between T/Y-dwarfs is often defined at around 500 K due to missing spectral observations of these cold and faint objects.[69] Future observations with JWST and the ELTs might improve the sample of Y-dwarfs with observed spectra. Y-dwarfs are dominated by deep spectral features of methane, water vapor and possibly absorption features of ammonia and water ice.[69] Vertical mixing, clouds, metallicity, photochemistry, lightning, impact shocks and metallic catalysts might influence the temperature at which the L/T and T/Y transition occurs.[68]

Secondary features

Brown dwarf spectral types
Secondary features
pec This suffix (e.g. L2pec) stands for "peculiar".[70]
sd This prefix (e.g. sdL0) stands for subdwarf and indicates a low metallicity and blue color[71]
β Objects with the beta (β) suffix (e.g. L4β) have an intermediate surface gravity.[72]
γ Objects with the gamma (γ) suffix (e.g. L5γ) have a low surface gravity.[72]
red The red suffix (e.g. L0red) indicates objects without signs of youth, but high dust content[73]
blue The blue suffix (e.g. L3blue) indicates unusual blue near-infrared colors for L dwarfs without obvious low metallicity[74]

Young brown dwarfs have low surface gravities because they have larger radii and lower masses compared to the field stars of similar spectral type. These sources are marked by a letter beta (β) for intermediate surface gravity and gamma (γ) for low surface gravity. Indication for low surface gravity are weak CaH, K I and Na I lines, as well as strong VO line.[72] Alpha (α) stands for normal surface gravity and is usually dropped. Sometimes an extremely low surface gravity is denoted by a delta (δ).[74] The suffix "pec" stands for peculiar. The peculiar suffix is still used for other features that are unusual and summarizes different properties, indicative of low surface gravity, subdwarfs and unresolved binaries.[75] The prefix sd stands for subdwarf and only includes cool subdwarfs. This prefix indicates a low metallicity and kinematic properties that are more similar to halo stars than to disk stars.[71] Subdwarfs appear bluer than disk objects.[76] The red suffix describes objects with red color, but an older age. This is not interpreted as low surface gravity, but as a high dust content.[73][74] The blue suffix describes objects with blue near-infrared colors that cannot be explained with low metallicity. Some are explained as L+T binaries, others are not binaries, such as 2MASS J11263991−5003550 and are explained with thin and/or large-grained clouds.[74]

Spectral and atmospheric properties of brown dwarfs

 
Artist's illustration of a brown dwarf's interior structure. Cloud layers at certain depths are offset as a result of layer shifting.

The majority of flux emitted by L and T dwarfs is in the 1- to 2.5-micrometre near-infrared range. Low and decreasing temperatures through the late-M, -L, and -T dwarf sequence result in a rich near-infrared spectrum containing a wide variety of features, from relatively narrow lines of neutral atomic species to broad molecular bands, all of which have different dependencies on temperature, gravity, and metallicity. Furthermore, these low temperature conditions favor condensation out of the gas state and the formation of grains.

 
Wind measured (Spitzer ST; Artist Concept; 9 Apr 2020)[77]

Typical atmospheres of known brown dwarfs range in temperature from 2,200 down to 750 K.[50] Compared to stars, which warm themselves with steady internal fusion, brown dwarfs cool quickly over time; more massive dwarfs cool more slowly than less massive ones. There is some evidence that the cooling of brown dwarfs slows down at the transition between spectral classes L and T (about 1000 K).[78]

Observations of known brown dwarf candidates have revealed a pattern of brightening and dimming of infrared emissions that suggests relatively cool, opaque cloud patterns obscuring a hot interior that is stirred by extreme winds. The weather on such bodies is thought to be extremely strong, comparable to but far exceeding Jupiter's famous storms.

On January 8, 2013, astronomers using NASA's Hubble and Spitzer space telescopes probed the stormy atmosphere of a brown dwarf named 2MASS J22282889–4310262, creating the most detailed "weather map" of a brown dwarf thus far. It shows wind-driven, planet-sized clouds. The new research is a stepping stone toward a better understanding not only brown dwarfs, but also of the atmospheres of planets beyond the Solar System.[79]

In April 2020 scientists reported clocking wind speeds of +650 ± 310 metres per second (up to 1,450 miles per hour) on the nearby brown dwarf 2MASS J10475385+2124234. To calculate the measurements, scientists compared the rotational movement of atmospheric features, as ascertained by brightness changes, against the electromagnetic rotation generated by the brown dwarf's interior. The results confirmed previous predictions that brown dwarfs would have high winds. Scientists are hopeful that this comparison method can be used to explore the atmospheric dynamics of other brown dwarfs and extrasolar planets.[80]

Observational techniques

 
Brown dwarfs Teide 1, Gliese 229B, and WISE 1828+2650 compared to red dwarf Gliese 229A, Jupiter and our Sun

Coronagraphs have recently been used to detect faint objects orbiting bright visible stars, including Gliese 229B.

Sensitive telescopes equipped with charge-coupled devices (CCDs) have been used to search distant star clusters for faint objects, including Teide 1.

Wide-field searches have identified individual faint objects, such as Kelu-1 (30 light-years away).

Brown dwarfs are often discovered in surveys to discover extrasolar planets. Methods of detecting extrasolar planets work for brown dwarfs as well, although brown dwarfs are much easier to detect.

Brown dwarfs can be powerful emitters of radio emission due to their strong magnetic fields. Observing programs at the Arecibo Observatory and the Very Large Array have detected over a dozen such objects, which are also called ultracool dwarfs because they share common magnetic properties with other objects in this class.[81] The detection of radio emission from brown dwarfs permits their magnetic field strengths to be measured directly.

Milestones

  • 1995: First brown dwarf verified. Teide 1, an M8 object in the Pleiades cluster, is picked out with a CCD in the Spanish Observatory of Roque de los Muchachos of the Instituto de Astrofísica de Canarias.
  • First methane brown dwarf verified. Gliese 229B is discovered orbiting red dwarf Gliese 229A (20 ly away) using an adaptive optics coronagraph to sharpen images from the 60-inch (1.5 m) reflecting telescope at Palomar Observatory on Southern California's Mt. Palomar; follow-up infrared spectroscopy made with their 200-inch (5.1 m) Hale telescope shows an abundance of methane.
  • 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the Chamaeleon I dark cloud, is determined to be an X-ray source, similar to convective late-type stars.
  • 15 December 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 MJ, 16 ly away) via the Chandra X-ray Observatory, catches a 2-hour flare.[82]
  • 27 July 2000: First radio emission (in flare and quiescence) detected from a brown dwarf. A team of students at the Very Large Array detected emission from LP 944-20.[83]
  • 30 April 2004: First detection of a candidate exoplanet around a brown dwarf: 2M1207b discovered with the VLT and the first directly imaged exoplanet.[84]
  • 20 March 2013: Discovery of the closest brown dwarf system: Luhman 16.[85]
  • 25 April 2014: Coldest-known brown dwarf discovered. WISE 0855−0714 is 7.2 light-years away (seventh-closest system to the Sun) and has a temperature between −48 to −13 °C.[63]

Brown dwarf as an X-ray source

 
Chandra image of LP 944-20 before flare and during flare

X-ray flares detected from brown dwarfs since 1999 suggest changing magnetic fields within them, similar to those in very-low-mass stars.

With no strong central nuclear energy source, the interior of a brown dwarf is in a rapid boiling, or convective state. When combined with the rapid rotation that most brown dwarfs exhibit, convection sets up conditions for the development of a strong, tangled magnetic field near the surface. The flare observed by Chandra from LP 944-20 could have its origin in the turbulent magnetized hot material beneath the brown dwarf's surface. A sub-surface flare could conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of lightning. The absence of X-rays from LP 944-20 during the non-flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2,800 K and becomes electrically neutral.

Using NASA's Chandra X-ray Observatory, scientists have detected X-rays from a low-mass brown dwarf in a multiple star system.[86] This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays.[86] "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of Chuo University in Tokyo.[86] "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi.[86] "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"[86]

Brown dwarfs as radio sources

The first brown dwarf that was discovered to emit radio signals was LP 944-20, which was observed based on its X-ray emission. Approximately 5–10% of brown dwarfs appear to have strong magnetic fields and emit radio waves, and there may be as many as 40 magnetic brown dwarfs within 25 pc of the Sun based on Monte Carlo modeling and their average spatial density.[87] The power of the radio emissions of brown dwarfs is roughly constant despite variations in their temperatures.[81] Brown dwarfs may maintain magnetic fields of up to 6 kG in strength.[88] Astronomers have estimated brown dwarf magnetospheres to span an altitude of approximately 107 m given properties of their radio emissions.[89] It is unknown whether the radio emissions from brown dwarfs more closely resemble those from planets or stars. Some brown dwarfs emit regular radio pulses, which are sometimes interpreted as radio emission beamed from the poles, but may also be beamed from active regions. The regular, periodic reversal of radio wave orientation may indicate that brown dwarf magnetic fields periodically reverse polarity. These reversals may be the result of a brown dwarf magnetic activity cycle, similar to the solar cycle.[90]

Binary brown dwarfs

 
Multi-epoch images of brown dwarf binaries taken with the Hubble Space Telescope. The binary Luhman 16 AB (left) is closer to the Solar System than the other examples shown here.

Observations of the orbit of binary systems containing brown dwarfs can be used to measure the mass of the brown dwarf. In the case of 2MASSW J0746425+2000321, the secondary weighs 6% of the solar mass. This measurement is called a dynamical mass.[91][92] The brown dwarf system closest to the Solar System is the binary Luhman 16. It was attempted to search for planets around this system with a similar method, but none were found.[93]

The wide binary system 2M1101AB was the first binary with a separation greater than 20 AU. The discovery of the system gave definitive insights to the formation of brown dwarfs. It was previously thought that wide binary brown dwarfs are not formed or at least are disrupted at ages of 1–10 Myr. The existence of this system is also inconsistent with the ejection hypothesis.[94] The ejection hypothesis was a proposed hypothesis in which brown dwarfs form in a multiple system, but are ejected before they gain enough mass to burn hydrogen.[95]

More recently the wide binary W2150AB was discovered. It has a similar mass ratio and binding energy as 2M1101AB, but a greater age and is located in a different region of the galaxy. While 2M1101AB is in a closely crowded region, the binary W2150AB is in a sparsely-separated field. It must have survived any dynamical interactions in its natal star cluster. The binary belongs also to a few L+T binaries that can be easily resolved by ground-based observatories. The other two are SDSS J1416+13AB and Luhman 16.[96]

There are other interesting binary systems such as the eclipsing binary brown dwarf system 2MASS J05352184–0546085.[97] Photometric studies of this system have revealed that the less massive brown dwarf in the system is hotter than its higher-mass companion.[98]

Brown dwarfs around white dwarfs are quite rare. GD 165B, the prototype of the L dwarfs, is one such system.[99] Systems with close, tidally locked brown dwarfs orbiting around white dwarfs belong to the post common envelope binaries or PCEBs. Only 8 confirmed PCEBs containing a white dwarf with a brown dwarf companion are known, including WD 0137-349 AB. In the past history of these close white dwarf-brown dwarf binaries, the brown dwarf is engulfed by the star in the red giant phase. Brown dwarfs with a mass lower than 20 Jupiter masses would evaporate during the engulfment.[100][101] The dearth of brown dwarfs orbiting close to white dwarfs can be compared with similar observations of brown dwarfs around main-sequence stars, described as the brown-dwarf desert.[102][103] The PCEB might evolve into a cataclysmic variable star (CV*) with the brown dwarf as the donor[104] and in the last stage of the system the binary might merge. The nova CK Vulpeculae might be a result of such a white dwarf–brown dwarf merger.[105][106]

Recent developments

 
A visualization representing a three-dimensional map of brown dwarfs (red dots) that have been discovered within 65 light-years of the Sun[107]

Estimates of brown dwarf populations in the solar neighbourhood suggest that there may be as many as six stars for every brown dwarf.[108] A more recent estimate from 2017 using the young massive star cluster RCW 38 concluded that the Milky Way galaxy contains between 25 and 100 billion brown dwarfs.[109] (Compare these numbers to the estimates of the number of stars in the Milky Way; 100 to 400 billion.)

In a study published in Aug 2017 NASA's Spitzer Space Telescope monitored infrared brightness variations in brown dwarfs caused by cloud cover of variable thickness. The observations revealed large-scale waves propagating in the atmospheres of brown dwarfs (similarly to the atmosphere of Neptune and other Solar System giant planets). These atmospheric waves modulate the thickness of the clouds and propagate with different velocities (probably due to differential rotation).[110]

In August 2020, astronomers discovered 95 brown dwarfs near the Sun through the project Backyard Worlds: Planet 9.[111]

Formation and evolution

 
The HH 1165 jet launched by the brown dwarf Mayrit 1701117 in the outer periphery of the sigma Orionis cluster

Brown dwarfs form similarly to stars and are surrounded by protoplanetary disks,[112] such as Cha 110913−773444. As of 2017 there is only one known proto-brown dwarf that is connected with a large Herbig-Haro object. This is the brown dwarf Mayrit 1701117, which is surrounded by a pseudo-disk and a Keplerian disk.[113] Mayrit 1701117 launches the 0.7-light-year-long jet H 1165, mostly seen in ionized sulfur.[114][115]

Disks around brown dwarfs have been found to have many of the same features as disks around stars; therefore, it is expected that there will be accretion-formed planets around brown dwarfs.[112] Given the small mass of brown dwarf disks, most planets will be terrestrial planets rather than gas giants.[116] If a giant planet orbits a brown dwarf across our line of sight, then, because they have approximately the same diameter, this would give a large signal for detection by transit.[117] The accretion zone for planets around a brown dwarf is very close to the brown dwarf itself, so tidal forces would have a strong effect.[116]

The brown dwarf Cha 110913−773444, located 500 light-years away in the constellation Chamaeleon, may be in the process of forming a miniature planetary system. Astronomers from Pennsylvania State University have detected what they believe to be a disk of gas and dust similar to the one hypothesized to have formed the Solar System. Cha 110913−773444 is the smallest brown dwarf found to date (8 MJ), and if it formed a planetary system, it would be the smallest-known object to have one.[118]

Planets around brown dwarfs

 
Artist's impression of a disc of dust and gas around a brown dwarf[119]

The super-Jupiter planetary-mass objects 2M1207b, 2MASS J044144 and Oph 98 B that are orbiting brown dwarfs at large orbital distances may have formed by cloud collapse rather than accretion and so may be sub-brown dwarfs rather than planets, which is inferred from relatively large masses and large orbits. The first discovery of a low-mass companion orbiting a brown dwarf (ChaHα8) at a small orbital distance using the radial velocity technique paved the way for the detection of planets around brown dwarfs on orbits of a few AU or smaller.[120][121] However, with a mass ratio between the companion and primary in ChaHα8 of about 0.3, this system rather resembles a binary star. Then, in 2008, the first planetary-mass companion in a relatively small orbit (MOA-2007-BLG-192Lb) was discovered orbiting a brown dwarf.[122]

Planets around brown dwarfs are likely to be carbon planets depleted of water.[123]

A 2017 study, based upon observations with Spitzer estimates that 175 brown dwarfs need to be monitored in order to guarantee (95%) at least one detection of a planet.[124]

Habitability

Habitability for hypothetical planets orbiting brown dwarfs has been studied. Computer models suggesting conditions for these bodies to have habitable planets are very stringent, the habitable zone being narrow, close (T dwarf 0.005 AU) and decreasing with time, due to the cooling of the brown dwarf (they fuse for at most 10 million years). The orbits there would have to be of extremely low eccentricity (on the order of 10 to the minus 6) to avoid strong tidal forces that would trigger a runaway greenhouse effect on the planets, rendering them uninhabitable. There would also be no moons.[125]

Superlative brown dwarfs

Main article: List of brown dwarfs

In 1984, it was postulated by some astronomers that the Sun may be orbited by an undetected brown dwarf (sometimes referred to as Nemesis) that could interact with the Oort cloud just as passing stars can. However, this hypothesis has fallen out of favor.[126]

Table of firsts

Record Name Spectral type RA/Dec Constellation Notes
First discovered Teide 1 (Pleiades Open Star Cluster) M8 3h47m18.0s +24°22'31" Taurus Imaged in 1989 and 1994
First imaged with coronography Gliese 229 B T6.5 06h10m34.62s −21°51'52.1" Lepus Discovered 1994
First with planemo 2M1207 M8 12h07m33.47s −39°32'54.0" Centaurus Planet discovered in 2004
First with a dust disk
First with bipolar outflow Rho-Oph 102 (SIMBAD: [GY92] 102) 16 26 42.758 -24 41 22.24 Ophiuchus partly resolved outflow[127]
First with large-scale Herbig-Haro object Mayrit 1701117

(Herbig-Haro object: HH 1165)

proto-BD 05 40 25.799 -02 48 55.42 Orion projected length of the Herbig-Haro object: 0.8 light-years (0.26 pc)[115]
First field type (solitary) Teide 1 M8 3h47m18.0s +24°22'31" Taurus 1995
First as a companion to a normal star Gliese 229 B T6.5 06h10m34.62s −21°51'52.1" Lepus 1995
First spectroscopic binary brown dwarf PPL 15 A, B[128] M6.5 Taurus Basri and Martín 1999
First eclipsing binary brown dwarf 2M0535-05[129][98] M6.5 Orion Stassun 2006, 2007 (distance ~450 pc)
First binary brown dwarf of T Type Epsilon Indi Ba, Bb[130] T1 + T6 Indus Distance: 3.626pc
First trinary brown dwarf DENIS-P J020529.0-115925 A/B/C L5, L8 and T0 02h05m29.40s −11°59'29.7" Cetus Delfosse et al. 1997[131]
First halo brown dwarf 2MASS J05325346+8246465 sdL7 05h32m53.46s +82°46'46.5" Gemini Burgasser et al. 2003[132]
First with late-M spectrum Teide 1 M8 3h47m18.0s +24°22'31" Taurus 1995
First with L spectrum GD 165B L4 14h 24m 39.144s 09° 17′ 13.98″ Boötes 1988
First with T spectrum Gliese 229 B T6.5 06h10m34.62s −21°51'52.1" Lepus 1995
Latest-T spectrum ULAS J003402.77−005206.7 T9[54] Cetus 2007
First with Y spectrum CFBDS0059[53] ~Y0 00h 59m 10.83s −01° 14′ 01.3″ Cetus 2008; this is also classified as a T9 dwarf, due to its close resemblance to other T dwarfs.[54]
First X-ray-emitting ChaHα1 M8 Chamaeleon 1998
First X-ray flare LP 944-20 M9V 03h39m35.22s −35°25'44.1" Fornax 1999
First radio emission (in flare and quiescence) LP 944-20 M9V 03h39m35.22s −35°25'44.1" Fornax 2000[83]
First potential brown dwarf auroras discovered LSR J1835+3259 M8.5 Lyra 2015
First detection of differential rotation in a brown dwarf TVLM 513-46546 M9 15h01m08.3s +22°50'02" Boötes Equator rotates faster than poles by 0.022 radians / day[133]
First confirmed brown dwarf to have survived the primary's red giant phase WD 0137−349 B[134] L8 01h 39m 42.847s −34° 42′ 39.32″ Sculptor (constellation)

Table of extremes

Record Name Spectral type RA/Dec Constellation Notes
Oldest COCONUTS-1B T4 03 55 56.871 +45 25 46.83 Perseus one of the few examples with a good age estimate: 7.3+2.8
−1.6 billion years[48]
Youngest 2MASS J05413280-0151272 M8.5 05h 41m 32.801s −01° 51′ 27.20″ Orion One brown dwarf member of the about 0.5 Myr-old Flame Nebula. 20.9 MJ object[135]
Most massive SDSS J010448.46+153501.8[136] usdL1.5 01h04m48.46s +15°35'01.8" Pisces distance is ~180–290 pc, mass is ~88.5–91.7 MJ. Transitional brown dwarfs.
Metal-rich
Metal-poor SDSS J010448.46+153501.8[136] usdL1.5 01h04m48.46s +15°35'01.8" Pisces distance is ~180–290 pc, metallicity is ~0.004 ZSol. Transitional brown dwarfs.
Least massive OTS 44 M9.5 11h 10m 11.5s −76° 32′ 13″ Chamaeleon Has a mass range of 11.5–15 MJ, distance is ~550 ly
Largest
Smallest
Fastest rotating 2MASS J03480772−6022270 T7 03h48m07.72s –60°22'27.1" Reticulum Rotational period of 1.080+0.004
−0.005[137]
Farthest KMT-2016-BLG-2142 b 17h 52m 27.0s –29° 23′ 04″ Sagittarius KMT-2016-BLG-2142 b (microlensing)[138] has a distance of 5,850 to 8,020 parsec. Could also be massive gas giant.
Nearest Luhman 16 AB L7.5 + T0.5 ± 1 10h 49m 18.723s −53° 19′ 09.86″ Vela Distance: ~6.5 ly
Brightest
Dimmest L 97-3B Y1 08h 06m 53.736s −66° 18′ 16.74″ Volans jmag=25.42
Hottest
Coolest WISE 0855−0714[63] Y4 08h 55m 10.83s −07° 14′ 42.5″ Hydra Temperature −48 to −13 °C
Coolest radio-flaring 2MASSI J10475385+2124234 T6.5 10h47m53.85s +21°24'23.4" Leo 900 K brown dwarf with 2.7 mJy bursts[139]
Most dense TOI-569b[140] Transiting brown dwarf TOI-569b has 64.1 MJ with a diameter 0.79 ± 0.02 times that of Jupiter. Density is 171.3g/cm3.
Least dense

Gallery

  •  

    Brown dwarf illustration[141]

See also

References

  1. ^ Sorahana, Satoko; Yamamura, Issei; Murakami, Hiroshi (2013). "On the Radii of Brown Dwarfs Measured with AKARI Near-infrared Spectroscopy". The Astrophysical Journal. 767 (1): 77. arXiv:1304.1259. Bibcode:2013ApJ...767...77S. doi:10.1088/0004-637X/767/1/77. We find that the brown dwarf radius ranges between 0.64–1.13 RJ with an average radius of 0.83 RJ.
  2. ^ Boss, Alan; McDowell, Tina (April 3, 2001). . Untitled Document. Carnegie Institution of Washington. Archived from the original on September 28, 2006. Retrieved March 31, 2022.
  3. ^ a b c Wethington, Nicholos (October 6, 2008). "Dense Exoplanet Creates Classification Calamity". Universe Today. Retrieved March 31, 2022.
  4. ^ a b c d Burgasser, Adam J. (June 2008). (PDF). Physics Today. Cambridge, MA: Massachusetts Institute of Technology. 61 (6): 70–71. Bibcode:2008PhT....61f..70B. doi:10.1063/1.2947658. Archived from the original (PDF) on May 8, 2013. Retrieved March 31, 2022 – via American Institute of Physics.
  5. ^ Springer, Cham (2014). Joergens, Viki (ed.). 50 Years of Brown Dwarfs. Astrophysics and Space Science Library. Vol. 401. SpringerLink. XI, 168. doi:10.1007/978-3-319-01162-2. eISSN 2214-7985. ISBN 978-3-319-01162-2. ISSN 0067-0057. Retrieved March 31, 2022.
  6. ^ a b Cain, Fraser (January 6, 2009). "If Brown Isn't a Color, What Color are Brown Dwarfs?". Retrieved 24 September 2013.
  7. ^ Burrows, Adam; Hubbard, William B.; Lunine, Jonathan I.; Liebert, James (2001). "The Theory of Brown Dwarfs and Extrasolar Giant Planets". Reviews of Modern Physics. 73 (3): 719–765. arXiv:astro-ph/0103383. Bibcode:2001RvMP...73..719B. doi:10.1103/RevModPhys.73.719. S2CID 204927572.
  8. ^ O'Neill, Ian (13 September 2011). "Violent Storms Rage on Nearby Brown Dwarf". Seeker.com.
  9. ^ Kumar, Shiv S. (1962). "Study of Degeneracy in Very Light Stars". Astronomical Journal. 67: 579. Bibcode:1962AJ.....67S.579K. doi:10.1086/108658.
  10. ^ Tarter, Jill (2014), "Brown is Not a Color: Introduction of the Term 'Brown Dwarf'", in Joergens, Viki (ed.), 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, vol. 401, Springer, pp. 19–24, doi:10.1007/978-3-319-01162-2_3, ISBN 978-3-319-01162-2
  11. ^ Croswell, Ken (1999). Planet Quest: The Epic Discovery of Alien Solar Systems. Oxford University Press. pp. 118–119. ISBN 978-0-192-88083-3.
  12. ^ "When will the Sun become a black dwarf?". Astronomy.com. April 10, 2020. Retrieved 2022-05-02.
  13. ^ Kumar, Shiv S. (1963). "The Structure of Stars of Very Low Mass". Astrophysical Journal. 137: 1121. Bibcode:1963ApJ...137.1121K. doi:10.1086/147589.
  14. ^ Hayashi, Chushiro; Nakano, Takenori (1963). "Evolution of Stars of Small Masses in the Pre-Main-Sequence Stages". Progress of Theoretical Physics. 30 (4): 460–474. Bibcode:1963PThPh..30..460H. doi:10.1143/PTP.30.460.
  15. ^ Nakano, Takenori (2014), "Pre-main Sequence Evolution and the Hydrogen-Burning Minimum Mass", in Joergens, Viki (ed.), 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, vol. 401, Springer, pp. 5–17, doi:10.1007/978-3-319-01162-2_2, ISBN 978-3-319-01162-2, S2CID 73521636
  16. ^ Martín, Eduardo L.; Basri, Gibor; Delfosse, Xavier; Forveille, Thierry (1997). "Keck HIRES spectra of the brown dwarf DENIS-P J1228.2-1547". Astronomy and Astrophysics. 327: L29–L32. Bibcode:1997A&A...327L..29M.
  17. ^ Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichmann, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E.; Skrutskie, Michael F. (1999). "Dwarfs Cooler than M: The Definition of Spectral Type L Using Discoveries from the 2 Micron All-Sky Survey (2MASS)" (PDF). The Astrophysical Journal. 519 (2): 802–833. Bibcode:1999ApJ...519..802K. doi:10.1086/307414. S2CID 73569208.
  18. ^ "Astronomers Announce First Clear Evidence of a Brown Dwarf". STScI. Retrieved 2019-10-23.
  19. ^ "Instituto de Astrofísica de Canarias, IAC". Iac.es. Retrieved 2013-03-16.
  20. ^ Rebolo, Rafael (2014), "Teide 1 and the Discovery of Brown Dwarfs", in Joergens, Viki (ed.), 50 Years of Brown Dwarfs – From Prediction to Discovery to Forefront of Research, Astrophysics and Space Science Library, vol. 401, Springer, pp. 25–50, doi:10.1007/978-3-319-01162-2_4, ISBN 978-3-319-01162-2
  21. ^ Rebolo, Rafael; Zapatero-Osorio, María Rosa; Martín, Eduardo L. (September 1995). "Discovery of a brown dwarf in the Pleiades star cluster". Nature. 377 (6545): 129–131. Bibcode:1995Natur.377..129R. doi:10.1038/377129a0. S2CID 28029538.
  22. ^ Leech, Kieron; Altieri, Bruno; Metcalfe, Liam; Martin, Eduardo L.; Rebolo, Rafael; Zapatero-Osorio, María Rosa; Laureijs, René J.; Prusti, Timo; Salama, Alberto; Siebenmorgen, Ralf; Claes, Peter; Trams, Norman (2000). "Mid-IR Observations of the Pleiades Brown Dwarfs Teide 1 & Calar 3". ASP Conference Series. 212: 82–87. Bibcode:2000ASPC..212...82L.
  23. ^ a b c d Kirkpatrick, J. Davy; Burgasser, Adam J. (6 November 2012). "Photometry, spectroscopy, and astrometry of M, L, and T dwarfs". DwarfArchives.org. Pasadena, CA: California Institute of Technology. Retrieved 2012-12-28. (M=536, L=918, T=355, Y=14)
  24. ^ McCaughrean, Mark J.; Close, Laird M.; Scholz, Ralf-Dieter; Lenzen, Rainer; Biller, Beth A.; Brandner, Wolfgang; Hartung, Markus; Lodieu, Nicolas (January 2004). "Epsilon Indi Ba/Bb: the nearest binary brown dwarf". Astronomy & Astrophysics. 413 (3): 1029–1036. arXiv:astro-ph/0309256. doi:10.1051/0004-6361:20034292. S2CID 15407249.
  25. ^ a b Forbes, John C.; Loeb, Abraham (February 2019), "On the Existence of Brown Dwarfs More Massive than the Hydrogen Burning Limit", The Astrophysical Journal, 871 (2): 11, arXiv:1805.12143, Bibcode:2019ApJ...871..227F, doi:10.3847/1538-4357/aafac8, S2CID 119059288, 227
  26. ^ Burrows, Adam; Hubbard, W. B.; Lunine, J. I.; Liebert, James (July 2001). "The theory of brown dwarfs and extrasolar giant planets". Reviews of Modern Physics. 73 (3): 719–765. arXiv:astro-ph/0103383. Bibcode:2001RvMP...73..719B. doi:10.1103/RevModPhys.73.719. S2CID 204927572. Hence the HBMM at solar metallicity and Yα = 50.25 is 0.07 – 0.074 M☉, ... while the HBMM at zero metallicity is 0.092 M☉
  27. ^ Kulkarni, Shrinivas R. (30 May 1997). "Brown Dwarfs: A Possible Missing Link Between Stars and Planets". Science. 276 (5317): 1350–1354. Bibcode:1997Sci...276.1350K. doi:10.1126/science.276.5317.1350.
  28. ^ Biller, Beth A.; Crossfield, Ian J. M.; Mancini, Luigi; Ciceri, Simona; Southworth, John; Kopytova, Taisiya G.; Bonnefoy, Mickaël; Deacon, Niall R.; Schlieder, Joshua E.; Buenzli, Esther; Brandner, Wolfgang; Allard, France; Homeier, Derek; Freytag, Bernd; Bailer-Jones, Coryn A. L.; Greiner, Jochen; Henning, Thomas; Goldman, Bertrand (6 November 2013). "Weather on the Nearest Brown Dwarfs: Resolved Simultaneous Multi-Wavelength Variability Monitoring of WISE J104915.57–531906.1AB". The Astrophysical Journal Letters. 778 (1): L10. arXiv:1310.5144. Bibcode:2013ApJ...778L..10B. doi:10.1088/2041-8205/778/1/l10. S2CID 56107487.
  29. ^ Basri, Gibor; Brown, Michael E. (2006-08-20). "Planetesimals to Brown Dwarfs: What is a Planet?". Annual Review of Earth and Planetary Sciences. 34 (2006): 193–216. arXiv:astro-ph/0608417. Bibcode:2006AREPS..34..193B. doi:10.1146/annurev.earth.34.031405.125058. S2CID 119338327.
  30. ^ Chen, Jingjing; Kipping, David (2016). "Probabilistic Forecasting of the Masses and Radii of Other Worlds". The Astrophysical Journal. 834 (1): 17. arXiv:1603.08614. doi:10.3847/1538-4357/834/1/17. S2CID 119114880. Retrieved 27 July 2021.
  31. ^ . Archived from the original on 2012-01-18. Retrieved 2013-03-15.
  32. ^ . Archived from the original on 2019-02-21. Retrieved 2019-02-11.
  33. ^ . IAU position statement. 2003-02-28. Archived from the original on 2014-12-16. Retrieved 2014-04-28.
  34. ^ Bodenheimer, Peter; D'Angelo, Gennaro; Lissauer, Jack J.; Fortney, Jonathan J.; Saumon, Didier (2013). "Deuterium Burning in Massive Giant Planets and Low-mass Brown Dwarfs Formed by Core-nucleated Accretion". The Astrophysical Journal. 770 (2): 120 (13 pp.). arXiv:1305.0980. Bibcode:2013ApJ...770..120B. doi:10.1088/0004-637X/770/2/120. S2CID 118553341.
  35. ^ Spiegel, David S.; Burrows, Adam; Milson, John A. (2011). "The Deuterium-Burning Mass Limit for Brown Dwarfs and Giant Planets". The Astrophysical Journal. 727 (1): 57. arXiv:1008.5150. Bibcode:2011ApJ...727...57S. doi:10.1088/0004-637X/727/1/57. S2CID 118513110.
  36. ^ Schneider, Jean; Dedieu, Cyril; Le Sidaner, Pierre; Savalle, Renaud; Zolotukhin, Ivan (2011). "Defining and cataloging exoplanets: The exoplanet.eu database". Astronomy & Astrophysics. 532 (79): A79. arXiv:1106.0586. Bibcode:2011A&A...532A..79S. doi:10.1051/0004-6361/201116713. S2CID 55994657.
  37. ^ Schneider, Jean (July 2016). "Exoplanets versus brown dwarfs: the CoRoT view and the future". The CoRoT Legacy Book. p. 157. arXiv:1604.00917. doi:10.1051/978-2-7598-1876-1.c038. ISBN 978-2-7598-1876-1. S2CID 118434022.
  38. ^ Hatzes, Artie P.; Rauer, Heike (2015). "A Definition for Giant Planets Based on the Mass-Density Relationship". The Astrophysical Journal. 810 (2): L25. arXiv:1506.05097. Bibcode:2015ApJ...810L..25H. doi:10.1088/2041-8205/810/2/L25. S2CID 119111221.
  39. ^ Wright, Jason T.; Fakhouri, Onsi; Marcy, Geoffrey W.; Han, Eunkyu; Feng, Y. Katherina; Johnson, John Asher; Howard, Andrew W.; Fischer, Debra A.; Valenti, Jeff A.; Anderson, Jay; Piskunov, Nikolai (2010). "The Exoplanet Orbit Database". Publications of the Astronomical Society of the Pacific. 123 (902): 412–422. arXiv:1012.5676. Bibcode:2011PASP..123..412W. doi:10.1086/659427. S2CID 51769219.
  40. ^ Exoplanet Criteria for Inclusion in the Archive, NASA Exoplanet Archive
  41. ^ Working Group on Extrasolar Planets – Definition of a "Planet" 2012-07-02 at the Wayback Machine Position statement on the definition of a "planet" (IAU)
  42. ^ Delorme, Philippe; Gagné, Jonathan; Malo, Lison; Reylé, Céline; Artigau, Étienne; Albert, Loïc; Forveille, Thierry; Delfosse, Xavier; Allard, France; Homeier, Derek (December 2012). "CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?". Astronomy & Astrophysics. 548: A26. arXiv:1210.0305. Bibcode:2012A&A...548A..26D. doi:10.1051/0004-6361/201219984. S2CID 50935950.
  43. ^ Luhman, Kevin L. (21 April 2014). "Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun". The Astrophysical Journal Letters. 786 (2): L18. arXiv:1404.6501. Bibcode:2014ApJ...786L..18L. doi:10.1088/2041-8205/786/2/L18. S2CID 119102654.
  44. ^ Saumon, Didier; Marley, Mark S. (December 2008). "The Evolution of L and T Dwarfs in Color-Magnitude Diagrams". Astrophysical Journal. 689 (2): 1327–1344. arXiv:0808.2611. Bibcode:2008ApJ...689.1327S. doi:10.1086/592734. ISSN 0004-637X. S2CID 15981010.
  45. ^ a b Marocco, Federico; Kirkpatrick, J. Davy; Meisner, Aaron M.; Caselden, Dan; Eisenhardt, Peter R. M.; Cushing, Michael C.; Faherty, Jacqueline K.; Gelino, Christopher R.; Wright, Edward L. (2020). "Improved infrared photometry and a preliminary parallax measurement for the extremely cold brown dwarf CWISEP J144606.62-231717.8". The Astrophysical Journal. 888 (2): L19. arXiv:1912.07692. Bibcode:2020ApJ...888L..19M. doi:10.3847/2041-8213/ab6201. S2CID 209386563.
  46. ^ Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline K.; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (September 2015). "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime". Astrophysical Journal. 810 (2): 158. arXiv:1508.01767. Bibcode:2015ApJ...810..158F. doi:10.1088/0004-637X/810/2/158. ISSN 0004-637X. S2CID 89611607.
  47. ^ Mohanty, Subhanjoy; Jayawardhana, Ray; Huélamo, Nuria; Mamajek, Eric (March 2007). "The Planetary Mass Companion 2MASS 1207-3932B: Temperature, Mass, and Evidence for an Edge-on Disk". Astrophysical Journal. 657 (2): 1064–1091. arXiv:astro-ph/0610550. Bibcode:2007ApJ...657.1064M. doi:10.1086/510877. ISSN 0004-637X. S2CID 17326111.
  48. ^ a b Zhang, Zhoujian; Liu, Michael C.; Hermes, James J.; Magnier, Eugene A.; Marley, Mark S.; Tremblay, Pier-Emmanuel; Tucker, Michael A.; Do, Aaron; Payne, Anna V.; Shappee, Benjamin J. (February 2020). "COol Companions ON Ultrawide orbiTS (COCONUTS). I. A High-Gravity T4 Benchmark around an Old White Dwarf and A Re-Examination of the Surface-Gravity Dependence of the L/T Transition". The Astrophysical Journal. 891 (2): 171. arXiv:2002.05723. Bibcode:2020ApJ...891..171Z. doi:10.3847/1538-4357/ab765c. S2CID 211126544.
  49. ^ Smart, Richard L.; Bucciarelli, Beatrice; Jones, Hugh R. A.; Marocco, Federico; Andrei, Alexandre Humberto; Goldman, Bertrand; Méndez, René A.; d'Avila, Victor de A.; Burningham, Ben; Camargo, Julio Ignácio Bueno de; Crosta, Maria Teresa; Daprà, Mario; Jenkins, James S.; Lachaume, Regis; Lattanzi, Mario G.; Penna, Jucira L.; Pinfield, David J.; da Silva Neto, Dario Nepomuceno; Sozzetti, Alessandro; Vecchiato, Alberto (December 2018). "Parallaxes of Southern Extremely Cool objects III: 118 L and T dwarfs". MNRAS. 481 (3): 3548–3562. arXiv:1811.00672. Bibcode:2018MNRAS.481.3548S. doi:10.1093/mnras/sty2520. ISSN 0035-8711. S2CID 119390019.
  50. ^ a b Burrows, Adam; Hubbard, William B.; Lunine, Jonathan I.; Liebert, James (2001). "The theory of brown dwarfs and extrasolar giant planets". Reviews of Modern Physics. 73 (3): 719–765. arXiv:astro-ph/0103383. Bibcode:2001RvMP...73..719B. doi:10.1103/RevModPhys.73.719. S2CID 204927572.
  51. ^ "An Artist's View of Brown Dwarf Types" 2011-11-17 at the Wayback Machine
  52. ^ a b c d Leggett, Sandy K.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Roellig, Thomas L.; Warren, Stephen J.; Burningham, Ben; Jones, Hugh R. A.; Kirkpatrick, J. Davy; Lodieu, Nicolas; Lucas, Philip W.; Mainzer, Amy K.; Martín, Eduardo L.; McCaughrean, Mark J.; Pinfield, David J.; Sloan, Gregory C.; Smart, Richard L.; Tamura, Motohide; Van Cleve, Jeffrey (2009). "The Physical Properties of Four ~600 K T Dwarfs". The Astrophysical Journal. 695 (2): 1517–1526. arXiv:0901.4093. Bibcode:2009ApJ...695.1517L. doi:10.1088/0004-637X/695/2/1517. S2CID 44050900..
  53. ^ a b Delorme, Philippe; Delfosse, Xavier; Albert, Loïc; Artigau, Étienne; Forveille, Thierry; Reylé, Céline; Allard, France; Homeier, Derek; Robin, Annie C.; Willott, Chris J.; Liu, Michael C.; Dupuy, Trent J. (2008). "CFBDS J005910.90-011401.3: Reaching the T–Y brown dwarf transition?". Astronomy and Astrophysics. 482 (3): 961–971. arXiv:0802.4387. Bibcode:2008A&A...482..961D. doi:10.1051/0004-6361:20079317. S2CID 847552.
  54. ^ a b c Burningham, Ben; Pinfield, David J.; Leggett, Sandy K.; Tamura, Motohide; Lucas, Philip W.; Homeier, Derek; Day-Jones, Avril; Jones, Hugh R. A.; Clarke, J. R. A.; Ishii, Miki; Kuzuhara, Masayuki; Lodieu, Nicolas; Zapatero-Osorio, María Rosa; Venemans, Bram Pieter; Mortlock, Daniel J.; Barrado y Navascués, David; Martín, Eduardo L.; Magazzù, Antonio (2008). "Exploring the substellar temperature regime down to ~550K". Monthly Notices of the Royal Astronomical Society. 391 (1): 320–333. arXiv:0806.0067. Bibcode:2008MNRAS.391..320B. doi:10.1111/j.1365-2966.2008.13885.x. S2CID 1438322.
  55. ^ Eisenhardt, Peter R. M.; Griffith, Roger L.; Stern, Daniel; Wright, Edward L.; Ashby, Matthew L. N.; Brodwin, Mark; Brown, Michael J. I.; Bussmann, R. S.; Dey, Arjun; Ghez, Andrea Mia; Glikman, Eilat; Gonzalez, Anthony H.; Kirkpatrick, J. Davy; Konopacky, Quinn; Mainzer, Amy; Vollbach, David; Wright, Shelley A. (2010). "Ultracool Field Brown Dwarf Candidates Selected at 4.5 microns". The Astronomical Journal. 139 (6): 2455. arXiv:1004.1436. Bibcode:2010AJ....139.2455E. doi:10.1088/0004-6256/139/6/2455. S2CID 2019463.
  56. ^ Luhman, Kevin L.; Burgasser, Adam J.; Bochanski, John J. (20 March 2011). "Discovery of a candidate for the coolest known brown dwarf". The Astrophysical Journal Letters. 730 (1): L9. arXiv:1102.5411. Bibcode:2011ApJ...730L...9L. doi:10.1088/2041-8205/730/1/L9. S2CID 54666396.
  57. ^ Rodriguez, David R.; Zuckerman, Benjamin; Melis, Carl; Song, Inseok (10 May 2011). "The ultra cool brown dwarf companion of WD 0806-661B: age, mass, and formation mechanism". The Astrophysical Journal. 732 (2): L29. arXiv:1103.3544. Bibcode:2011ApJ...732L..29R. doi:10.1088/2041-8205/732/2/L29. S2CID 118382542.
  58. ^ Liu, Michael C.; Delorme, Philippe; Dupuy, Trent J.; Bowler, Brendan P.; Albert, Loïc; Artigau, Étienne; Reylé, Céline; Forveille, Thierry; Delfosse, Xavier (28 Feb 2011). "CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System". The Astrophysical Journal. 740 (2): 108. arXiv:1103.0014. Bibcode:2011ApJ...740..108L. doi:10.1088/0004-637X/740/2/108. S2CID 118344589.
  59. ^ Plait, Phil (24 August 2011). "WISE finds coolest brown dwarfs ever seen!". Discover Magazine.
  60. ^ Clavin, Whitney (8 June 2012). "WISE Finds Few Brown Dwarfs Close To Home". NASA.
  61. ^ Morse, Jon. . Archived from the original on 7 October 2011. Retrieved 24 August 2011.
  62. ^ Beichman, Charles A.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Barman, Travis S.; Marsh, Kenneth A.; Cushing, Michael C.; Wright, Edward L. (2013). "The Coldest Brown Dwarf (or Free-floating Planet)?: The Y Dwarf WISE 1828+2650". The Astrophysical Journal. 764 (1): 101. arXiv:1301.1669. Bibcode:2013ApJ...764..101B. doi:10.1088/0004-637X/764/1/101. S2CID 118575478.
  63. ^ a b c Clavin, Whitney; Harrington, J. D. (25 April 2014). "NASA's Spitzer and WISE Telescopes Find Close, Cold Neighbor of Sun". NASA.gov. from the original on 26 April 2014.
  64. ^ Eisenhardt, Peter R. M.; Marocco, Federico; Fowler, John W.; Meisner, Aaron M.; Kirkpatrick, J. Davy; Garcia, Nelson; Jarrett, Thomas H.; Koontz, Renata; Marchese, Elijah J.; Stanford, S. Adam; Caselden, Dan (2020). "The CatWISE Preliminary Catalog: Motions from WISE and NEOWISE Data". The Astrophysical Journal Supplement Series. 247 (2): 69. arXiv:1908.08902. Bibcode:2020ApJS..247...69E. doi:10.3847/1538-4365/ab7f2a. S2CID 201645245.
  65. ^ Meisner, Aaron M.; Caselden, Dan; Kirkpatrick, J. Davy; Marocco, Federico; Gelino, Christopher R.; Cushing, Michael C.; Eisenhardt, Peter R. M.; Wright, Edward L.; Faherty, Jacqueline K.; Koontz, Renata; Marchese, Elijah J. (2020). "Expanding the Y Dwarf Census with Spitzer Follow-up of the Coldest CatWISE Solar Neighborhood Discoveries". The Astrophysical Journal. 889 (2): 74. arXiv:1911.12372. Bibcode:2020ApJ...889...74M. doi:10.3847/1538-4357/ab6215. S2CID 208513044.
  66. ^ Marocco, Federico; Caselden, Dan; Meisner, Aaron M.; Kirkpatrick, J. Davy; Wright, Edward L.; Faherty, Jacqueline K.; Gelino, Christopher R.; Eisenhardt, Peter R. M.; Fowler, John W.; Cushing, Michael C.; Cutri, Roc M.; Garcia, Nelson; Jarrett, Thomas H.; Koontz, Renata; Mainzer, Amanda; Marchese, Elijah J.; Mobasher, Bahram; Schlegel, David J.; Stern, Daniel; Teplitz, Harry I. (2019). "CWISEP J193518.59 − 154620.3: An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISE". The Astrophysical Journal. 881 (1): 17. arXiv:1906.08913. Bibcode:2019ApJ...881...17M. doi:10.3847/1538-4357/ab2bf0. S2CID 195316522.
  67. ^ Bardalez Gagliuffi, Daniella C.; Faherty, Jacqueline K.; Backyard Worlds: Planet 9 Citizen Science Collaboration; Schneider, Adam C.; Meisner, Aaron M.; Caselden, Dan; Colin, Guillaume; Goodman, Sam; Kirkpatrick, J. Davy; Kuchner, Marc J.; Gagne, Jonathan; Logsdon, Sarah E.; Burgasser, Adam J.; Allers, Katelyn N.; Debes, John H.; Wisniewski, John (January 2020). "WISE J0830+2837: the first Y dwarf from Backyard Worlds: Planet 9". AAS. 52: 132.06. Bibcode:2020AAS...23513206B.
  68. ^ a b c Zahnle, Kevin J.; Marley, Mark S. (2014-12-01). "Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets". The Astrophysical Journal. 797 (1): 41. arXiv:1408.6283. Bibcode:2014ApJ...797...41Z. doi:10.1088/0004-637X/797/1/41. ISSN 0004-637X. S2CID 118509317.
  69. ^ a b Bardalez Gagliuffi, Daniella C.; Faherty, Jacqueline K.; Schneider, Adam C.; Meisner, Aaron; Caselden, Dan; Colin, Guillaume; Goodman, Sam; Kirkpatrick, J. Davy; Kuchner, Marc; Gagné, Jonathan; Logsdon, Sarah E.; Burgasser, Adam J.; Allers, Katelyn; Debes, John; Wisniewski, John (2020-06-01). "WISEA J083011.95+283716.0: A Missing Link Planetary-mass Object". The Astrophysical Journal. 895 (2): 145. arXiv:2004.12829. Bibcode:2020ApJ...895..145B. doi:10.3847/1538-4357/ab8d25. ISSN 0004-637X. S2CID 216553879.
  70. ^ "Spectral type codes". simbad.u-strasbg.fr. Retrieved 2020-03-06.
  71. ^ a b Burningham, Ben; Smith, Leigh; Cardoso, Cátia V.; Lucas, Philip W.; Burgasser, Adam J.; Jones, Hugh R. A.; Smart, Richard L. (May 2014). "The discovery of a T6.5 subdwarf". Monthly Notices of the Royal Astronomical Society. 440 (1): 359–364. arXiv:1401.5982. Bibcode:2014MNRAS.440..359B. doi:10.1093/mnras/stu184. ISSN 0035-8711. S2CID 119283917.
  72. ^ a b c Cruz, Kelle L.; Kirkpatrick, J. Davy; Burgasser, Adam J. (February 2009). "Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5". The Astronomical Journal. 137 (2): 3345–3357. arXiv:0812.0364. Bibcode:2009AJ....137.3345C. doi:10.1088/0004-6256/137/2/3345. ISSN 0004-6256. S2CID 15376964.
  73. ^ a b Looper, Dagny L.; Kirkpatrick, J. Davy; Cutri, Roc M.; Barman, Travis; Burgasser, Adam J.; Cushing, Michael C.; Roellig, Thomas; McGovern, Mark R.; McLean, Ian S.; Rice, Emily; Swift, Brandon J. (October 2008). "Discovery of Two Nearby Peculiar L Dwarfs from the 2MASS Proper-Motion Survey: Young or Metal-Rich?". Astrophysical Journal. 686 (1): 528–541. arXiv:0806.1059. Bibcode:2008ApJ...686..528L. doi:10.1086/591025. ISSN 0004-637X. S2CID 18381182.
  74. ^ a b c d Kirkpatrick, J. Davy; Looper, Dagny L.; Burgasser, Adam J.; Schurr, Steven D.; Cutri, Roc M.; Cushing, Michael C.; Cruz, Kelle L.; Sweet, Anne C.; Knapp, Gillian R.; Barman, Travis S.; Bochanski, John J. (September 2010). "Discoveries from a Near-infrared Proper Motion Survey Using Multi-epoch Two Micron All-Sky Survey Data". Astrophysical Journal Supplement Series. 190 (1): 100–146. arXiv:1008.3591. Bibcode:2010ApJS..190..100K. doi:10.1088/0067-0049/190/1/100. ISSN 0067-0049. S2CID 118435904.
  75. ^ Faherty, Jacqueline K.; Riedel, Adric R.; Cruz, Kelle L.; Gagne, Jonathan; Filippazzo, Joseph C.; Lambrides, Erini; Fica, Haley; Weinberger, Alycia; Thorstensen, John R.; Tinney, Chris G.; Baldassare, Vivienne (July 2016). "Population Properties of Brown Dwarf Analogs to Exoplanets". Astrophysical Journal Supplement Series. 225 (1): 10. arXiv:1605.07927. Bibcode:2016ApJS..225...10F. doi:10.3847/0067-0049/225/1/10. ISSN 0067-0049. S2CID 118446190.
  76. ^ Reid, Neill. "Colour-magnitude data". www.stsci.edu. Retrieved 2020-03-06.
  77. ^ National Radio Astronomy Observatory (9 April 2020). "Astronomers measure wind speed on a brown dwarf – Atmosphere, interior rotating at different speeds". EurekAlert!. Retrieved 10 April 2020.
  78. ^ Chen, Minghan; Li, Yiting; Brandt, Timothy D.; Dupuy, Trent J.; Cardoso, Cátia V.; McCaughrean, Mark J. (2022). "Precise Dynamical Masses of ε Indi Ba and Bb: Evidence of Slowed Cooling at the L/T Transition". The Astronomical Journal. 163 (6): 288. arXiv:2205.08077. Bibcode:2022AJ....163..288C. doi:10.3847/1538-3881/ac66d2. S2CID 248834536.
  79. ^ . Hubblesite. NASA. Archived from the original on 2 April 2014. Retrieved 8 January 2013.
  80. ^ "Astronomers Clock High Winds on Object Outside Our Solar System". CNN.com. CNN. 9 April 2020. Retrieved 11 April 2020.
  81. ^ a b Route, Matthew; Wolszczan, Alexander (20 October 2016). "The Second Arecibo Search for 5 GHz Radio Flares from Ultracool Dwarfs". The Astrophysical Journal. 830 (2): 85. arXiv:1608.02480. Bibcode:2016ApJ...830...85R. doi:10.3847/0004-637X/830/2/85. S2CID 119279978.
  82. ^ Rutledge, Robert E.; Basri, Gibor; Martín, Eduardo L.; Bildsten, Lars (1 August 2000). "Chandra Detection of an X-Ray Flare from the Brown Dwarf LP 944-20". The Astrophysical Journal. 538 (2): L141–L144. arXiv:astro-ph/0005559. Bibcode:2000ApJ...538L.141R. doi:10.1086/312817. S2CID 17800872.
  83. ^ a b Berger, Edo; Ball, Steven; Becker, Kate M.; Clarke, Melanie; Frail, Dale A.; Fukuda, Therese A.; Hoffman, Ian M.; Mellon, Richard; Momjian, Emmanuel; Murphy, Nathanial W.; Teng, Stacey H.; Woodruff, Timothy; Zauderer, B. Ashley; Zavala, Robert T. (2001-03-15). . Nature (Submitted manuscript). 410 (6826): 338–340. arXiv:astro-ph/0102301. Bibcode:2001Natur.410..338B. doi:10.1038/35066514. PMID 11268202. S2CID 4411256. Archived from the original on 2021-04-27.
  84. ^ Chauvin, Gael; Zuckerman, Ben; Lagrange, Anne-Marie. "Yes, it is the Image of an Exoplanet: Astronomers Confirm the First Image of a Planet Outside of Our Solar System" (Press release). European Southern Observatory. Retrieved 2020-02-09.
  85. ^ Luhman, Kevin L. (April 2013). "Discovery of a Binary Brown Dwarf at 2 pc from the Sun". Astrophysical Journal Letters. 767 (1): L1. arXiv:1303.2401. Bibcode:2013ApJ...767L...1L. doi:10.1088/2041-8205/767/1/L1. ISSN 0004-637X. S2CID 8419422.
  86. ^ a b c d e . April 14, 2003. Archived from the original on December 30, 2010. Retrieved March 19, 2010.
  87. ^ Route, Matthew (10 August 2017). "Radio-flaring Ultracool Dwarf Population Synthesis". The Astrophysical Journal. 845 (1): 66. arXiv:1707.02212. Bibcode:2017ApJ...845...66R. doi:10.3847/1538-4357/aa7ede. S2CID 118895524.
  88. ^ Kao, Melodie M.; Hallinan, Gregg; Pineda, J. Sebastian; Stevenson, David; Burgasser, Adam J. (31 July 2018). "The Strongest Magnetic Fields on the Coolest Brown Dwarfs". The Astrophysical Journal Supplement Series. 237 (2): 25. arXiv:1808.02485. Bibcode:2018ApJS..237...25K. doi:10.3847/1538-4365/aac2d5. S2CID 118898602.
  89. ^ Route, Matthew (10 July 2017). "Is WISEP J060738.65+242953.4 Really A Magnetically Active, Pole-on L Dwarf?". The Astrophysical Journal. 843 (2): 115. arXiv:1706.03010. Bibcode:2017ApJ...843..115R. doi:10.3847/1538-4357/aa78ab. S2CID 119056418.
  90. ^ Route, Matthew (20 October 2016). "The Discovery of Solar-like Activity Cycles Beyond the End of the Main Sequence?". The Astrophysical Journal Letters. 830 (2): L27. arXiv:1609.07761. Bibcode:2016ApJ...830L..27R. doi:10.3847/2041-8205/830/2/L27. S2CID 119111063.
  91. ^ Bouy, Hervé. "Weighing Ultra-Cool Stars - Large Ground-Based Telescopes and Hubble Team-Up to Perform First Direct Brown Dwarf Mass Measurement" (Press release). European Southern Observatory. Retrieved 2019-12-11.
  92. ^ Bouy, Hervé; Duchêne, Gaspard; Köhler, Rainer; Brandner, Wolfgang; Bouvier, Jérôme; Martín, Eduardo L.; Ghez, Andrea Mia; Delfosse, Xavier; Forveille, Thierry; Allard, France; Baraffe, Isabelle; Basri, Gibor; Close, Laird M.; McCabe, Caer E. (2004-08-01). "First determination of the dynamical mass of a binary L dwarf". Astronomy & Astrophysics. 423 (1): 341–352. arXiv:astro-ph/0405111. Bibcode:2004A&A...423..341B. doi:10.1051/0004-6361:20040551. ISSN 0004-6361. S2CID 3149721.
  93. ^ Bedin, Luigi R.; Pourbaix, Dimitri; Apai, Dániel; Burgasser, Adam J.; Buenzli, Esther; Boffin, Henri M. J.; Libralato, Mattia (2017-09-01). "Hubble Space Telescope astrometry of the closest brown dwarf binary system – I. Overview and improved orbit". Monthly Notices of the Royal Astronomical Society. 470 (1): 1140–1155. arXiv:1706.00657. doi:10.1093/mnras/stx1177. hdl:10150/625503. ISSN 0035-8711. S2CID 119385778.
  94. ^ Luhman, Kevin L. (2004-10-10). "The First Discovery of a Wide Binary Brown Dwarf". The Astrophysical Journal. 614 (1): 398–403. arXiv:astro-ph/0407344. Bibcode:2004ApJ...614..398L. doi:10.1086/423666. ISSN 0004-637X. S2CID 11733526.
  95. ^ Reipurth, Bo; Clarke, Cathie (June 2003). "Brown Dwarfs as Ejected Stellar Embryos: Observational Perspectives". IAUS. 211: 13–22. arXiv:astro-ph/0209005. Bibcode:2003IAUS..211...13R. doi:10.1017/s0074180900210188. ISSN 1743-9221. S2CID 16822178.
  96. ^ Faherty, Jacqueline K.; Goodman, Sam; Caselden, Dan; Colin, Guillaume; Kuchner, Marc J.; Meisner, Aaron M.; Gagné, Jonathan; Schneider, Adam C.; Gonzales, Eileen C.; Bardalez Gagliuffi, Daniella C.; Logsdon, Sarah E. (2020). "WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9". The Astrophysical Journal. 889 (2): 176. arXiv:1911.04600. Bibcode:2020ApJ...889..176F. doi:10.3847/1538-4357/ab5303. S2CID 207863267.
  97. ^ Stassun, Keivan G.; Mathieu, Robert D.; Valenti, Jeff A. (March 2006). "Discovery of two young brown dwarfs in an eclipsing binary system". Nature. 440 (7082): 311–314. Bibcode:2006Natur.440..311S. doi:10.1038/nature04570. ISSN 0028-0836. PMID 16541067. S2CID 4310407.
  98. ^ a b Stassun, Keivan G.; Mathieu, Robert D.; Valenti, Jeff A. (2007). "A Surprising Reversal of Temperatures in the Brown-Dwarf Eclipsing Binary 2MASS J05352184-0546085". The Astrophysical Journal. 664 (2): 1154–1166. arXiv:0704.3106. Bibcode:2007ApJ...664.1154S. doi:10.1086/519231. S2CID 15144741.
  99. ^ Farihi, Jay; Christopher, Micol (October 2004). "A Possible Brown Dwarf Companion to the White Dwarf GD 1400". The Astronomical Journal. 128 (4): 1868. arXiv:astro-ph/0407036. Bibcode:2004AJ....128.1868F. doi:10.1086/423919. ISSN 1538-3881. S2CID 119530628.
  100. ^ Maxted, Pierre; Napiwotzki, Ralf; Dobbie, Paul; Burleigh, Matt. "A Sub-Stellar Jonah – Brown Dwarf Survives Being Swallowed" (Press release). European Southern Observatory. Retrieved 2019-12-11.
  101. ^ Casewell, Sarah L.; Braker, Ian P.; Parsons, Steven G.; Hermes, James J.; Burleigh, Matthew R.; Belardi, Claudia; Chaushev, Alexander; Finch, Nicolle L.; Roy, Mervyn; Littlefair, Stuart P.; Goad, Mike; Dennihy, Erik (31 January 2018). "The first sub-70 min non-interacting WD–BD system: EPIC212235321". Monthly Notices of the Royal Astronomical Society. 476 (1): 1405–1411. arXiv:1801.07773. Bibcode:2018MNRAS.476.1405C. doi:10.1093/mnras/sty245. ISSN 0035-8711. S2CID 55776991.
  102. ^ Longstaff, Emma S.; Casewell, Sarah L.; Wynn, Graham A.; Maxted, Pierre F. L.; Helling, Christiane (2017-10-21). "Emission lines in the atmosphere of the irradiated brown dwarf WD0137−349B". Monthly Notices of the Royal Astronomical Society. 471 (2): 1728–1736. arXiv:1707.05793. Bibcode:2017MNRAS.471.1728L. doi:10.1093/mnras/stx1786. ISSN 0035-8711. S2CID 29792989.
  103. ^ Grether, Daniel; Lineweaver, Charles H. (April 2006). "How Dry is the Brown Dwarf Desert? Quantifying the Relative Number of Planets, Brown Dwarfs, and Stellar Companions around Nearby Sun‐like Stars". The Astrophysical Journal. 640 (2): 1051–1062. arXiv:astro-ph/0412356. Bibcode:2006ApJ...640.1051G. doi:10.1086/500161. ISSN 0004-637X.
  104. ^ Rappaport, Saul A.; Vanderburg, Andrew; Nelson, Lorne; Gary, Bruce L.; Kaye, Thomas G.; Kalomeni, Belinda; Howell, Steve B.; Thorstensen, John R.; Lachapelle, François-René; Lundy, Matthew; St-Antoine, Jonathan (2017-10-11). "WD 1202-024: the shortest-period pre-cataclysmic variable". Monthly Notices of the Royal Astronomical Society. 471 (1): 948–961. arXiv:1705.05863. Bibcode:2017MNRAS.471..948R. doi:10.1093/mnras/stx1611. ISSN 0035-8711. S2CID 119349942.
  105. ^ Lira, Nicolás; Blue, Charles E.; Turner, Calum; Hiramatsu, Masaaki. . ALMA Observatory. Archived from the original on 2019-10-22. Retrieved 2019-11-12.
  106. ^ Eyres, Stewart P. S.; Evans, Aneurin; Zijlstra, Albert; Avison, Adam; Gehrz, Robert D.; Hajduk, Marcin; Starrfield, Sumner; Mohamed, Shazrene; Woodward, Charles E.; Wagner, R. Mark (2018-12-21). "ALMA reveals the aftermath of a white dwarf–brown dwarf merger in CK Vulpeculae". Monthly Notices of the Royal Astronomical Society. 481 (4): 4931–4939. arXiv:1809.05849. Bibcode:2018MNRAS.481.4931E. doi:10.1093/mnras/sty2554. ISSN 0035-8711. S2CID 119462149.
  107. ^ Meisner, Aaron; Kocz, Amanda. "Mapping Our Sun's Backyard". NOIRLab. Retrieved 1 February 2021.
  108. ^ O'Neill, Ian (12 June 2012). "Brown Dwarfs, Runts of Stellar Litter, Rarer than Thought". Space.com. Retrieved 2012-12-28.
  109. ^ Muzic, Koraljka; Schoedel, Rainer; Scholz, Alexander; Geers, Vincent C.; Jayawardhana, Ray; Ascenso, Joana; Cieza, Lucas A. (2017-07-02). "The low-mass content of the massive young star cluster RCW 38". Monthly Notices of the Royal Astronomical Society. 471 (3): 3699–3712. arXiv:1707.00277. Bibcode:2017MNRAS.471.3699M. doi:10.1093/mnras/stx1906. ISSN 0035-8711. S2CID 54736762.
  110. ^ Apai, Dániel; Karalidi, T.; Marley, Mark S.; Yang, H.; Flateau, D.; Metchev, S.; Cowan, N. B.; Buenzli, E.; Burgasser, Adam J.; Radigan, J.; Artigau, Étienne; Lowrance, P. (2017). "Zones, spots, and planetary-scale waves beating in brown dwarf atmospheres". Science. 357 (6352): 683–687. Bibcode:2017Sci...357..683A. doi:10.1126/science.aam9848. PMID 28818943.
  111. ^ Gohd, Chelsea (19 August 2020). "Volunteers spot almost 100 cold brown dwarfs near our sun". Space.com.
  112. ^ a b Apai, Dániel; Pascucci, Ilaria; Bouwman, Jeroen; Natta, Antonella; Henning, Thomas; Dullemond, Cornelis P. (2005). "The Onset of Planet Formation in Brown Dwarf Disks". Science. 310 (5749): 834–6. arXiv:astro-ph/0511420. Bibcode:2005Sci...310..834A. doi:10.1126/science.1118042. PMID 16239438. S2CID 5181947.
  113. ^ Riaz, Basmah; Machida, Masahiro N.; Stamatellos, Dimitris (July 2019). "ALMA reveals a pseudo-disc in a proto-brown dwarf". Monthly Notices of the Royal Astronomical Society. 486 (3): 4114–4129. arXiv:1904.06418. Bibcode:2019MNRAS.486.4114R. doi:10.1093/mnras/stz1032. ISSN 0035-8711. S2CID 119286540.
  114. ^ Riaz, Basmah; Najita, Joan. . National Optical Astronomy Observatory. Archived from the original on 2020-02-18. Retrieved 2020-02-18.
  115. ^ a b Riaz, Basmah; Briceño, Cesar; Whelan, Emma T.; Heathcote, Stephen (July 2017). "First Large-scale Herbig-Haro Jet Driven by a Proto-brown Dwarf". Astrophysical Journal. 844 (1): 47. arXiv:1705.01170. Bibcode:2017ApJ...844...47R. doi:10.3847/1538-4357/aa70e8. ISSN 0004-637X. S2CID 119080074.
  116. ^ a b Burrows, Adam; Hubbard, William B.; Lunine, Jonathan I.; Liebert, James (2011). "Tidal evolution of planets around brown dwarfs". Astronomy & Astrophysics. 535: A94. arXiv:1109.2906. Bibcode:2011A&A...535A..94B. doi:10.1051/0004-6361/201117734. S2CID 118532416.
  117. ^ Jewitt, David C., Pan-STARRS Science Overview 2015-10-16 at the Wayback Machine
  118. ^ Luhman, Kevin L.; Adame, Lucía; d'Alessio, Paola; Calvet, Nuria; Hartmann, Lee; Megeath, S. T.; Fazio, G. G. (2005). "Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk". The Astrophysical Journal. 635 (1): L93–L96. arXiv:astro-ph/0511807. Bibcode:2005ApJ...635L..93L. doi:10.1086/498868. S2CID 11685964.
  119. ^ Ricci, Luca; Testi, Leonardo; Pierce-Price, Douglas; Stoke, John. (Press release). European Southern Observatory. Archived from the original on 3 December 2012. Retrieved 3 December 2012.
  120. ^ Joergens, Viki; Müller, André (2007). "16–20 MJup Radial Velocity Companion Orbiting the Brown Dwarf Candidate Cha Hα 8". The Astrophysical Journal. 666 (2): L113–L116. arXiv:0707.3744. Bibcode:2007ApJ...666L.113J. doi:10.1086/521825. S2CID 119140521.
  121. ^ Joergens, Viki; Müller, André; Reffert, Sabine (2010). "Improved radial velocity orbit of the young binary brown dwarf candidate Cha Hα 8". Astronomy and Astrophysics. 521 (A24): A24. arXiv:1006.2383. Bibcode:2010A&A...521A..24J. doi:10.1051/0004-6361/201014853. S2CID 54989533.
  122. ^ Bennet, David P.; Bond, Ian A.; Udalski, Andrzej; Sumi, Takahiro; Abe, Fumio; Fukui, Akihiko; Furusawa, Kei; Hearnshaw, John B.; Holderness, Sarah; Itow, Yoshitaka; Kamiya, Koki; Korpela, Aarno V.; Kilmartin, Pamela M.; Lin, Wei; Ling, Cho Hong; Masuda, Kimiaki; Matsubara, Yutaka; Miyake, Noriyuki; Muraki, Yasushi; Nagaya, Maiko; Okumura, Teppei; Ohnishi, Kouji; Perrott, Yvette C.; Rattenbury, Nicholas J.; Sako, Takashi; Saito, Toshiharu; Sato, S.; Skuljan, Ljiljana; Sullivan, Denis J.; Sweatman, Winston L.; Tristram, Paul J.; Yock, Philip C. M.; Kubiak, Marcin; Szymański, Michał K.; Pietrzyński, Grzegorz; Soszyński, Igor; Szewczyk, O.; Wyrzykowski, Łukasz; Ulaczyk, Krzysztof; Batista, Virginie; Beaulieu, Jean-Philippe; Brillant, Stéphane; Cassan, Arnaud; Fouqué, Pascal; Kervella, Pierre; Kubas, Daniel; Marquette, Jean-Baptiste (30 May 2008). "A Low-Mass Planet with a Possible Sub-Stellar-Mass Host in Microlensing Event MOA-2007-BLG-192". The Astrophysical Journal. 684 (1): 663–683. arXiv:0806.0025. Bibcode:2008ApJ...684..663B. doi:10.1086/589940. S2CID 14467194.
  123. ^ Burrows, Adam; Hubbard, William B.; Lunine, Jonathan I.; Liebert, James (2013). "The Atomic and Molecular Content of Disks Around Very Low-mass Stars and Brown Dwarfs". The Astrophysical Journal. 779 (2): 178. arXiv:1311.1228. Bibcode:2013ApJ...779..178P. doi:10.1088/0004-637X/779/2/178. S2CID 119001471.
  124. ^ He, Matthias Y.; Triaud, Amaury H. M. J.; Gillon, Michaël (January 2017). "First limits on the occurrence rate of short-period planets orbiting brown dwarfs". Monthly Notices of the Royal Astronomical Society. 464 (3): 2687–2697. arXiv:1609.05053. Bibcode:2017MNRAS.464.2687H. doi:10.1093/mnras/stw2391. S2CID 53692008.
  125. ^ Barnes, Rory; Heller, René (2011). "Habitable Planets Around White and Brown Dwarfs: The Perils of a Cooling Primary". Astrobiology. 13 (3): 279–291. arXiv:1211.6467. Bibcode:2013AsBio..13..279B. doi:10.1089/ast.2012.0867. PMC 3612282. PMID 23537137.
  126. ^ Morrison, David (2 August 2011). "Scientists today no longer think an object like Nemesis could exist". NASA Ask An Astrobiologist. Archived from the original on 13 December 2012. Retrieved 2011-10-22.
  127. ^ Whelan, Emma T.; Ray, Thomas P.; Bacciotti, Francesca; Natta, Antonella; Testi, Leonardo; Randich, Sofia (June 2005). "A resolved outflow of matter from a brown dwarf". Nature. 435 (7042): 652–654. arXiv:astro-ph/0506485. Bibcode:2005Natur.435..652W. doi:10.1038/nature03598. ISSN 0028-0836. PMID 15931217. S2CID 4415442.
  128. ^ Basri, Gibor; Martín, Eduardo L. (1999). "[astro-ph/9908015] PPl 15: The First Brown Dwarf Spectroscopic Binary". The Astronomical Journal. 118 (5): 2460–2465. arXiv:astro-ph/9908015. Bibcode:1999AJ....118.2460B. doi:10.1086/301079. S2CID 17662168.
  129. ^ Stassun, Keivan G; Mathieu, Robert D; Valenti, Jeff A (2006-03-16). "Discovery of two young brown dwarfs in an eclipsing binary system". Nature. 440 (7082): 311–314. Bibcode:2006Natur.440..311S. doi:10.1038/nature04570. PMID 16541067. S2CID 4310407.
  130. ^ Scholz, Ralf-Dieter; McCaughrean, Mark (2003-01-13). (Press release). European Southern Observatory. Archived from the original on October 13, 2008. Retrieved 2013-03-16.
  131. ^ Burrows, Adam; Hubbard, William B.; Lunine, Jonathan I.; Liebert, James (2004). "A possible third component in the L dwarf binary system DENIS-P J020529.0-115925 discovered with the Hubble Space Telescope". The Astronomical Journal. 129 (1): 511–517. arXiv:astro-ph/0410226. Bibcode:2005AJ....129..511B. doi:10.1086/426559. S2CID 119336794.
  132. ^ Burgasser, Adam J.; Kirkpatrick, J. Davy; Burrows, Adam; Liebert, James; Reid, I. Neill; Gizis, John E.; McGovern, Mark R.; Prato, Lisa; McLean, Ian S. (2003). "The First Substellar Subdwarf? Discovery of a Metal-Poor L Dwarf with Halo Kinematics". The Astrophysical Journal. 592 (2): 1186–1192. arXiv:astro-ph/0304174. Bibcode:2003ApJ...592.1186B. doi:10.1086/375813. S2CID 11895472.
  133. ^ Wolszczan, Alexander; Route, Matthew (2014). "Timing Analysis of the Periodic Radio and Optical Brightness Variations of the Ultracool Dwarf, TVLM 513-46546". The Astrophysical Journal. 788 (1): 23. arXiv:1404.4682. Bibcode:2014ApJ...788...23W. doi:10.1088/0004-637X/788/1/23. S2CID 119114679.
  134. ^ Maxted, Pierre F. L.; Napiwotzki, Ralf; Dobbie, Paul D.; Burleigh, Matthew R. (2006). . Nature (Submitted manuscript). 442 (7102): 543–5. arXiv:astro-ph/0608054. Bibcode:2006Natur.442..543M. doi:10.1038/nature04987. hdl:2299/1227. PMID 16885979. S2CID 4368344. Archived from the original on 2021-04-27.
  135. ^ Levine, Joanna L.; Steinhauer, Aaron; Elston, Richard J.; Lada, Elizabeth A. (2006-08-01). "Low-Mass Stars and Brown Dwarfs in NGC 2024: Constraints on the Substellar Mass Function". The Astrophysical Journal. 646 (2): 1215–1229. arXiv:astro-ph/0604315. Bibcode:2006ApJ...646.1215L. doi:10.1086/504964. ISSN 0004-637X. S2CID 118955538. Table 3: FLMN_J0541328-0151271
  136. ^ a b Zhang, ZengHua; Homeier, Derek; Pinfield, David J.; Lodieu, Nicolas; Jones, Hugh R. A.; Pavlenko, Yakiv V. (2017-06-11). "Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object". Monthly Notices of the Royal Astronomical Society. 468 (1): 261. arXiv:1702.02001. Bibcode:2017MNRAS.468..261Z. doi:10.1093/mnras/stx350. S2CID 54847595.
  137. ^ Tannock, Megan E.; Metchev, Stanimir; Heinze, Aren; Miles-Páez, Paulo A.; Gagné, Jonathan; Burgasser, Adam J.; Marley, Mark S.; Apai, Dániel; Suárez, Genaro; Plavchan, Peter (March 2021). "Weather on Other Worlds. V. The Three Most Rapidly Rotating Ultra-cool Dwarfs". The Astronomical Journal. 161 (5): 224. arXiv:2103.01990. Bibcode:2021AJ....161..224T. doi:10.3847/1538-3881/abeb67. S2CID 232105126.
  138. ^ "The Extrasolar Planet Encyclopaedia — KMT-2016-BLG-2142 b". exoplanet.eu. Retrieved 2021-01-12.
  139. ^ Route, Matthew; Wolszczan, Alexander (2012). "The Arecibo Detection of the Coolest Radio-flaring Brown Dwarf". The Astrophysical Journal. 2012 (747): L22. arXiv:1202.1287. Bibcode:2012ApJ...747L..22R. doi:10.1088/2041-8205/747/2/L22. S2CID 119290950.
  140. ^ Astrobites (24 June 2020). "Transiting Brown Dwarfs from TESS 2". AAS Nova. Retrieved 2013-03-16.
  141. ^ Tannock, Megan; Metchev, Stanimir; Kocz, Amanda (7 April 2021). "Caught Speeding: Clocking the Fastest-Spinning Brown Dwarfs". NOIRLab. Retrieved 9 April 2021.

External links

 
Look up brown dwarf in Wiktionary, the free dictionary.
 
Wikimedia Commons has media related to Brown dwarf.
  • HubbleSite newscenter – Weather patterns on a brown dwarf
  • Allard, France; Homeier, Derek (2007). "Brown dwarfs". Scholarpedia. 2 (12): 4475. Bibcode:2007SchpJ...2.4475A. doi:10.4249/scholarpedia.4475.

History

  • Kumar, Shiv S.; Low-Luminosity Stars. Gordon and Breach, London, 1969—an early overview paper on brown dwarfs

Details

  • A current list of L and T dwarfs
  • , contrasted with stars and planets (via Berkeley)
  • I. Neill Reid's pages at the Space Telescope Science Institute:
  • First X-ray from brown dwarf observed, Spaceref.com, 2000
  • Montes, David; "Brown Dwarfs and ultracool dwarfs (late-M, L, T)", UCM
  • Wild Weather: Iron Rain on Failed Stars—scientists are investigating astonishing weather patterns on brown dwarfs, Space.com, 2006
  • NASA Brown dwarf detectives—Detailed information in a simplified sense
  • Brown Dwarfs—Website with general information about brown dwarfs (has many detailed and colorful artist's impressions)

Stars

  • stats and history
  • (not all confirmed), 1998
  • Luhman, Kevin L.; Adame, Lucía; d'Alessio, Paola; Calvet, Nuria; Hartmann, Lee; Megeath, S. Thomas; Fazio, Giovanni G. (2005). "Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk". The Astrophysical Journal. 635 (1): L93–L96. arXiv:astro-ph/0511807. Bibcode:2005ApJ...635L..93L. doi:10.1086/498868. S2CID 11685964.
  • Deacon, Niall R.; and Hambly, Nigel C.; "Y-Spectral class for Ultra-Cool Dwarfs", 2006

January 29, 2023
brown, dwarf, also, called, failed, stars, substellar, objects, that, massive, enough, sustain, nuclear, fusion, ordinary, hydrogen, into, helium, their, cores, unlike, main, sequence, star, instead, they, have, mass, between, most, massive, giant, planets, le. Brown dwarfs also called failed stars are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen 1H into helium in their cores unlike a main sequence star Instead they have a mass between the most massive gas giant planets and the least massive stars approximately 13 to 80 times that of Jupiter MJ 2 3 However they can fuse deuterium 2H and the most massive ones gt 65 MJ can fuse lithium 7Li 3 Artist s concept of a T type brown dwarfComparison most brown dwarfs are slightly larger than Jupiter 15 20 1 but are still up to 80 times more massive due to greater density Image is to scale with Jupiter s radius being 10 times that of Earth and the Sun s radius is 10 times that of Jupiter Astronomers classify self luminous objects by spectral class a distinction intimately tied to the surface temperature and brown dwarfs occupy types M L T and Y 4 5 As brown dwarfs do not undergo stable hydrogen fusion they cool down over time progressively passing through later spectral types as they age Despite their name to the naked eye brown dwarfs would appear in different colors depending on their temperature 4 The warmest ones are possibly orange or red 6 while cooler brown dwarfs would likely appear magenta or black to the human eye 4 7 Brown dwarfs may be fully convective with no layers or chemical differentiation by depth 8 Though their existence was initially theorized in the 1960s it was not until the mid 1990s that the first unambiguous brown dwarfs were discovered As brown dwarfs have relatively low surface temperatures they are not very bright at visible wavelengths emitting most of their light in the infrared However with the advent of more capable infrared detecting devices thousands of brown dwarfs have been identified The nearest known brown dwarfs are located in the Luhman 16 system a binary of L and T type brown dwarfs about 6 5 light years 2 0 parsecs away from the Sun Luhman 16 is the third closest system to the Sun after Alpha Centauri and Barnard s Star Contents 1 History 1 1 Early theorizing 1 2 Deuterium fusion 1 3 GD 165B and class L 1 4 Gliese 229B and class T 1 5 Teide 1 and class M 2 Theory 2 1 High mass brown dwarfs versus low mass stars 2 1 1 The lithium test 2 1 2 Atmospheric methane 2 1 3 Iron rain 2 2 Low mass brown dwarfs versus high mass planets 2 2 1 Size and fuel burning ambiguities 2 2 2 Heat spectrum 2 2 3 Current IAU standard 2 2 4 Sub brown dwarf 2 3 Role of other physical properties in the mass estimate 3 Observations 3 1 Classification of brown dwarfs 3 1 1 Spectral class M 3 1 2 Spectral class L 3 1 3 Spectral class T 3 1 4 Spectral class Y 3 1 5 Role of vertical mixing 3 1 6 Secondary features 3 2 Spectral and atmospheric properties of brown dwarfs 3 3 Observational techniques 3 4 Milestones 3 5 Brown dwarf as an X ray source 3 6 Brown dwarfs as radio sources 3 7 Binary brown dwarfs 3 8 Recent developments 4 Formation and evolution 5 Planets around brown dwarfs 5 1 Habitability 6 Superlative brown dwarfs 6 1 Table of firsts 6 2 Table of extremes 7 Gallery 8 See also 9 References 10 External links 10 1 History 10 2 Details 10 3 StarsHistory Edit The smaller object is Gliese 229B about 20 to 50 times the mass of Jupiter orbiting the star Gliese 229 It is in the constellation Lepus about 19 light years from Earth Early theorizing Edit Planets brown dwarfs stars not to scale The objects now called brown dwarfs were theorized by Shiv S Kumar in the 1960s to exist and were originally called black dwarfs 9 a classification for dark substellar objects floating freely in space that were not massive enough to sustain hydrogen fusion However a the term black dwarf was already in use to refer to a cold white dwarf b red dwarfs fuse hydrogen and c these objects may be luminous at visible wavelengths early in their lives Because of this alternative names for these objects were proposed including planetar and substar In 1975 Jill Tarter suggested the term brown dwarf using brown as an approximate color 6 10 11 The term black dwarf still refers to a white dwarf that has cooled to the point that it no longer emits significant amounts of light However the time required for even the lowest mass white dwarf to cool to this temperature is calculated to be longer than the current age of the universe hence such objects are expected to not yet exist 12 Early theories concerning the nature of the lowest mass stars and the hydrogen burning limit suggested that a population I object with a mass less than 0 07 solar masses M or a population II object less than 0 09 M would never go through normal stellar evolution and would become a completely degenerate star 13 The first self consistent calculation of the hydrogen burning minimum mass confirmed a value between 0 07 and 0 08 solar masses for population I objects 14 15 Deuterium fusion Edit The discovery of deuterium burning down to 0 013 M 13 6 jupiter mass and the impact of dust formation in the cool outer atmospheres of brown dwarfs in the late 1980s brought these theories into question However such objects were hard to find because they emit almost no visible light Their strongest emissions are in the infrared IR spectrum and ground based IR detectors were too imprecise at that time to readily identify any brown dwarfs Since then numerous searches by various methods have sought these objects These methods included multi color imaging surveys around field stars imaging surveys for faint companions of main sequence dwarfs and white dwarfs surveys of young star clusters and radial velocity monitoring for close companions GD 165B and class L Edit For many years efforts to discover brown dwarfs were fruitless In 1988 however a faint companion to the white dwarf star GD 165 was found in an infrared search of white dwarfs The spectrum of the companion GD 165B was very red and enigmatic showing none of the features expected of a low mass red dwarf It became clear that GD 165B would need to be classified as a much cooler object than the latest M dwarfs then known GD 165B remained unique for almost a decade until the advent of the Two Micron All Sky Survey 2MASS which discovered many objects with similar colors and spectral features Today GD 165B is recognized as the prototype of a class of objects now called L dwarfs 16 17 Although the discovery of the coolest dwarf was highly significant at the time it was debated whether GD 165B would be classified as a brown dwarf or simply a very low mass star because observationally it is very difficult to distinguish between the two citation needed Soon after the discovery of GD 165B other brown dwarf candidates were reported Most failed to live up to their candidacy however because the absence of lithium showed them to be stellar objects True stars burn their lithium within a little over 100 Myr whereas brown dwarfs which can confusingly have temperatures and luminosities similar to true stars will not Hence the detection of lithium in the atmosphere of an object older than 100 Myr ensures that it is a brown dwarf Gliese 229B and class T Edit The first class T brown dwarf was discovered in 1994 by Caltech astronomers Shrinivas Kulkarni Tadashi Nakajima Keith Matthews and Rebecca Oppenheimer 18 and Johns Hopkins scientists Samuel T Durrance and David Golimowski It was confirmed in 1995 as a substellar companion to Gliese 229 Gliese 229b is one of the first two instances of clear evidence for a brown dwarf along with Teide 1 Confirmed in 1995 both were identified by the presence of the 670 8 nm lithium line The latter was found to have a temperature and luminosity well below the stellar range Its near infrared spectrum clearly exhibited a methane absorption band at 2 micrometres a feature that had previously only been observed in the atmospheres of giant planets and that of Saturn s moon Titan Methane absorption is not expected at any temperature of a main sequence star This discovery helped to establish yet another spectral class even cooler than L dwarfs known as T dwarfs for which Gliese 229B is the prototype Teide 1 and class M Edit The first confirmed class M brown dwarf was discovered by Spanish astrophysicists Rafael Rebolo head of team Maria Rosa Zapatero Osorio and Eduardo L Martin in 1994 19 This object found in the Pleiades open cluster received the name Teide 1 The discovery article was submitted to Nature in May 1995 and published on 14 September 1995 20 21 Nature highlighted Brown dwarfs discovered official in the front page of that issue Teide 1 was discovered in images collected by the IAC team on 6 January 1994 using the 80 cm telescope IAC 80 at Teide Observatory and its spectrum was first recorded in December 1994 using the 4 2 m William Herschel Telescope at Roque de los Muchachos Observatory La Palma The distance chemical composition and age of Teide 1 could be established because of its membership in the young Pleiades star cluster Using the most advanced stellar and substellar evolution models at that moment the team estimated for Teide 1 a mass of 55 15 MJ 22 which is below the stellar mass limit The object became a reference in subsequent young brown dwarf related works In theory a brown dwarf below 65 MJ is unable to burn lithium by thermonuclear fusion at any time during its evolution This fact is one of the lithium test principles used to judge the substellar nature of low luminosity and low surface temperature astronomical bodies High quality spectral data acquired by the Keck 1 telescope in November 1995 showed that Teide 1 still had the initial lithium abundance of the original molecular cloud from which Pleiades stars formed proving the lack of thermonuclear fusion in its core These observations confirmed that Teide 1 is a brown dwarf as well as the efficiency of the spectroscopic lithium test For some time Teide 1 was the smallest known object outside the Solar System that had been identified by direct observation Since then over 1 800 brown dwarfs have been identified 23 even some very close to Earth like Epsilon Indi Ba and Bb a pair of brown dwarfs gravitationally bound to a Sun like star 12 light years from the Sun 24 and Luhman 16 a binary system of brown dwarfs at 6 5 light years from the Sun Theory EditThis section needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed July 2020 Learn how and when to remove this template message Hertzsprung Russell diagram Spectral type O B A F G K M L T Brown dwarfs White dwarfs Red dwarfs Subdwarfs Main sequence dwarfs Subgiants Giants Red giants Blue giants Bright giants Supergiants Red supergiant Hypergiants absolutemagni tude MV The standard mechanism for star birth is through the gravitational collapse of a cold interstellar cloud of gas and dust As the cloud contracts it heats due to the Kelvin Helmholtz mechanism Early in the process the contracting gas quickly radiates away much of the energy allowing the collapse to continue Eventually the central region becomes sufficiently dense to trap radiation Consequently the central temperature and density of the collapsed cloud increases dramatically with time slowing the contraction until the conditions are hot and dense enough for thermonuclear reactions to occur in the core of the protostar For most stars gas and radiation pressure generated by the thermonuclear fusion reactions within the core of the star will support it against any further gravitational contraction Hydrostatic equilibrium is reached and the star will spend most of its lifetime fusing hydrogen into helium as a main sequence star If however the initial 25 mass of the protostar is less than about 0 08 M 26 normal hydrogen thermonuclear fusion reactions will not ignite in the core Gravitational contraction does not heat the small protostar very effectively and before the temperature in the core can increase enough to trigger fusion the density reaches the point where electrons become closely packed enough to create quantum electron degeneracy pressure According to the brown dwarf interior models typical conditions in the core for density temperature and pressure are expected to be the following 10 g c m 3 r c 10 3 g c m 3 displaystyle 10 mathrm g cm 3 lesssim rho c lesssim 10 3 mathrm g cm 3 T c 3 10 6 K displaystyle T c lesssim 3 times 10 6 mathrm K P c 10 5 M b a r displaystyle P c sim 10 5 mathrm Mbar This means that the protostar is not massive enough and not dense enough to ever reach the conditions needed to sustain hydrogen fusion The infalling matter is prevented by electron degeneracy pressure from reaching the densities and pressures needed Further gravitational contraction is prevented and the result is a failed star or brown dwarf that simply cools off by radiating away its internal thermal energy Note that in principle it is possible for a brown dwarf to slowly accrete mass above the hydrogen burning limit without initiating hydrogen fusion This could happen via mass transfer in a binary brown dwarf system 25 High mass brown dwarfs versus low mass stars Edit Lithium is generally present in brown dwarfs and not in low mass stars Stars which reach the high temperature necessary for fusing hydrogen rapidly deplete their lithium Fusion of lithium 7 and a proton occurs producing two helium 4 nuclei The temperature necessary for this reaction is just below that necessary for hydrogen fusion Convection in low mass stars ensures that lithium in the whole volume of the star is eventually depleted Therefore the presence of the lithium spectral line in a candidate brown dwarf is a strong indicator that it is indeed a substellar object The lithium test Edit The use of lithium to distinguish candidate brown dwarfs from low mass stars is commonly referred to as the lithium test and was pioneered by Rafael Rebolo Eduardo Martin and Antonio Magazzu However lithium is also seen in very young stars which have not yet had enough time to burn it all Heavier stars like the Sun can also retain lithium in their outer layers which never get hot enough to fuse lithium and whose convective layer does not mix with the core where the lithium would be rapidly depleted Those larger stars are easily distinguishable from brown dwarfs by their size and luminosity Conversely brown dwarfs at the high end of their mass range can be hot enough to deplete their lithium when they are young Dwarfs of mass greater than 65 MJ can burn their lithium by the time they are half a billion years old 27 thus the lithium test is not perfect Atmospheric methane Edit Unlike stars older brown dwarfs are sometimes cool enough that over very long periods of time their atmospheres can gather observable quantities of methane which cannot form in hotter objects Dwarfs confirmed in this fashion include Gliese 229B Iron rain Edit Main sequence stars cool but eventually reach a minimum bolometric luminosity that they can sustain through steady fusion This varies from star to star but is generally at least 0 01 that of the Sun citation needed Brown dwarfs cool and darken steadily over their lifetimes sufficiently old brown dwarfs will be too faint to be detectable Iron rain as part of atmospheric convection processes is possible only in brown dwarfs and not in small stars The spectroscopy research into iron rain is still ongoing but not all brown dwarfs will always have this atmospheric anomaly In 2013 a heterogeneous iron containing atmosphere was imaged around the B component in the nearby Luhman 16 system 28 Low mass brown dwarfs versus high mass planets Edit An artistic concept of the brown dwarf around the star HD 29587 a companion known as HD 29587 b and estimated to be about 55 Jupiter masses Like stars brown dwarfs form independently but unlike stars lack sufficient mass to ignite Like all stars they can occur singly or in close proximity to other stars Some orbit stars and can like planets have eccentric orbits Size and fuel burning ambiguities Edit Brown dwarfs are all roughly the same radius as Jupiter At the high end of their mass range 60 90 MJ the volume of a brown dwarf is governed primarily by electron degeneracy pressure 29 as it is in white dwarfs at the low end of the range 10 MJ their volume is governed primarily by Coulomb pressure as it is in planets The net result is that the radii of brown dwarfs vary by only 10 15 over the range of possible masses Moreover the mass radius relationship shows no change from about one Saturn mass to the onset of hydrogen burning 0 080 0 008 M suggesting that from this perspective brown dwarfs are simply high mass Jovian planets 30 This can make distinguishing them from planets difficult In addition many brown dwarfs undergo no fusion even those at the high end of the mass range over 60 MJ cool quickly enough that after 10 million years they no longer undergo fusion Heat spectrum Edit X ray and infrared spectra are telltale signs of brown dwarfs Some emit X rays and all warm dwarfs continue to glow tellingly in the red and infrared spectra until they cool to planet like temperatures under 1 000 K Gas giants have some of the characteristics of brown dwarfs Like the Sun Jupiter and Saturn are both made primarily of hydrogen and helium Saturn is nearly as large as Jupiter despite having only 30 the mass Three of the giant planets in the Solar System Jupiter Saturn and Neptune emit much more up to about twice heat than they receive from the Sun 31 32 All four giant planets have their own planetary systems in the form of extensive moon systems Current IAU standard Edit Currently the International Astronomical Union considers an object above 13 MJ the limiting mass for thermonuclear fusion of deuterium to be a brown dwarf whereas an object under that mass and orbiting a star or stellar remnant is considered a planet The minimum mass required to trigger sustained hydrogen burning about 80 MJ forms the upper limit of the definition 3 33 It is also debated whether brown dwarfs would be better defined by their formation process rather than by theoretical mass limits based on nuclear fusion reactions 4 Under this interpretation brown dwarfs are those objects that represent the lowest mass products of the star formation process while planets are objects formed in an accretion disk surrounding a star The coolest free floating objects discovered such as WISE 0855 as well as the lowest mass young objects known like PSO J318 5 22 are thought to have masses below 13 MJ and as a result are sometimes referred to as planetary mass objects due to the ambiguity of whether they should be regarded as rogue planets or brown dwarfs There are planetary mass objects known to orbit brown dwarfs such as 2M1207b MOA 2007 BLG 192Lb 2MASS J044144b and Oph 98 B The 13 Jupiter mass cutoff is a rule of thumb rather than something of precise physical significance Larger objects will burn most of their deuterium and smaller ones will burn only a little and the 13 Jupiter mass value is somewhere in between 34 The amount of deuterium burnt also depends to some extent on the composition of the object specifically on the amount of helium and deuterium present and on the fraction of heavier elements which determines the atmospheric opacity and thus the radiative cooling rate 35 As of 2011 the Extrasolar Planets Encyclopaedia included objects up to 25 Jupiter masses saying The fact that there is no special feature around 13 MJup in the observed mass spectrum reinforces the choice to forget this mass limit 36 As of 2016 this limit was increased to 60 Jupiter masses 37 based on a study of mass density relationships 38 The Exoplanet Data Explorer includes objects up to 24 Jupiter masses with the advisory The 13 Jupiter mass distinction by the IAU Working Group is physically unmotivated for planets with rocky cores and observationally problematic due to the sin i ambiguity 39 The NASA Exoplanet Archive includes objects with a mass or minimum mass equal to or less than 30 Jupiter masses 40 Sub brown dwarf Edit Main article Sub brown dwarf A size comparison between the Sun a young sub brown dwarf and Jupiter As the sub brown dwarf ages it will gradually cool and shrink Objects below 13 MJ called sub brown dwarf or planetary mass brown dwarf form in the same manner as stars and brown dwarfs i e through the collapse of a gas cloud but have a mass below the limiting mass for thermonuclear fusion of deuterium 41 Some researchers call them free floating planets 42 whereas others call them planetary mass brown dwarfs 43 Role of other physical properties in the mass estimate Edit While spectroscopic features can help to distinguish between low mass stars and brown dwarfs it is often necessary to estimate the mass to come to a conclusion The theory behind the mass estimate is that brown dwarfs with a similar mass form in a similar way and are hot when they form Some have spectral types that are similar to low mass stars such as 2M1101AB As they cool down the brown dwarfs should retain a range of luminosities depending on the mass 44 Without the age and luminosity a mass estimate is difficult for example an L type brown dwarf could be an old brown dwarf with a high mass possibly a low mass star or a young brown dwarf with a very low mass For Y dwarfs this is less of a problem as they remain low mass objects near the sub brown dwarf limit even for relative high age estimates 45 For L and T dwarfs it is still useful to have an accurate age estimate The luminosity is here the less concerning property as this can be estimated from the spectral energy distribution 46 The age estimate can be done in two ways Either the brown dwarf is young and still has spectral features that are associated with youth or the brown dwarf co moves with a star or stellar group star cluster or association which have easier to obtain age estimates A very young brown dwarf that was further studied with this method is 2M1207 and the companion 2M1207b Based on the location proper motion and spectral signature this object was determined to belong to the 8 million year old TW Hydrae association and the mass of the secondary was determined to be below the deuterium burning limit with 8 2 MJ 47 A very old example of an age estimate that makes use of co movement is the brown dwarf white dwarf binary COCONUTS 1 with the white dwarf having a total age of 7 3 2 8 1 6 billion years In this case the mass was not estimated with the derived age but the co movement provided an accurate distance estimate using Gaia parallax Using this measurement the authors estimated the radius which was then used to estimate the mass for the brown dwarf as 15 4 0 9 0 8 MJ 48 Observations EditClassification of brown dwarfs Edit Spectral class M Edit Artist s vision of a late M dwarf These are brown dwarfs with a spectral class of M5 5 or later they are also called late M dwarfs These can be considered red dwarfs in the eyes of some scientists citation needed Many brown dwarfs with spectral type M are young objects such as Teide 1 Spectral class L Edit Artist s vision of an L dwarf The defining characteristic of spectral class M the coolest type in the long standing classical stellar sequence is an optical spectrum dominated by absorption bands of titanium II oxide TiO and vanadium II oxide VO molecules However GD 165B the cool companion to the white dwarf GD 165 had none of the hallmark TiO features of M dwarfs The subsequent identification of many objects like GD 165B ultimately led to the definition of a new spectral class the L dwarfs defined in the red optical region of the spectrum not by metal oxide absorption bands TiO VO but by metal hydride emission bands FeH CrH MgH CaH and prominent atomic lines of alkali metals Na K Rb Cs As of 2013 update over 900 L dwarfs have been identified 23 most by wide field surveys the Two Micron All Sky Survey 2MASS the Deep Near Infrared Survey of the Southern Sky DENIS and the Sloan Digital Sky Survey SDSS This spectral class contains not only the brown dwarfs because the coolest main sequence stars above brown dwarfs gt 80 MJ have the spectral class L2 to L6 49 Spectral class T Edit Artist s vision of a T dwarf As GD 165B is the prototype of the L dwarfs Gliese 229B is the prototype of a second new spectral class the T dwarfs T dwarfs are pinkish magenta Whereas near infrared NIR spectra of L dwarfs show strong absorption bands of H2O and carbon monoxide CO the NIR spectrum of Gliese 229B is dominated by absorption bands from methane CH4 features that were found only in the giant planets of the Solar System and Titan CH4 H2O and molecular hydrogen H2 collision induced absorption CIA give Gliese 229B blue near infrared colors Its steeply sloped red optical spectrum also lacks the FeH and CrH bands that characterize L dwarfs and instead is influenced by exceptionally broad absorption features from the alkali metals Na and K These differences led J Davy Kirkpatrick to propose the T spectral class for objects exhibiting H and K band CH4 absorption As of 2013 update 355 T dwarfs are known 23 NIR classification schemes for T dwarfs have recently been developed by Adam Burgasser and Tom Geballe Theory suggests that L dwarfs are a mixture of very low mass stars and sub stellar objects brown dwarfs whereas the T dwarf class is composed entirely of brown dwarfs Because of the absorption of sodium and potassium in the green part of the spectrum of T dwarfs the actual appearance of T dwarfs to human visual perception is estimated to be not brown but magenta 50 51 T class brown dwarfs such as WISE 0316 4307 have been detected more than 100 light years from the Sun Spectral class Y Edit Artist s vision of a Y dwarf In 2009 the coolest known brown dwarfs had estimated effective temperatures between 500 and 600 K 227 327 C 440 620 F and have been assigned the spectral class T9 Three examples are the brown dwarfs CFBDS J005910 90 011401 3 ULAS J133553 45 113005 2 and ULAS J003402 77 005206 7 52 The spectra of these objects have absorption peaks around 1 55 micrometres 52 Delorme et al have suggested that this feature is due to absorption from ammonia and that this should be taken as indicating the T Y transition making these objects of type Y0 52 53 However the feature is difficult to distinguish from absorption by water and methane 52 and other authors have stated that the assignment of class Y0 is premature 54 In April 2010 two newly discovered ultracool sub brown dwarfs UGPS 0722 05 and SDWFS 1433 35 were proposed as prototypes for spectral class Y0 55 In February 2011 Luhman et al reported the discovery of WD 0806 661B a brown dwarf companion to a nearby white dwarf with a temperature of c 300 K 27 C 80 F and mass of 7 MJ 56 Though of planetary mass Rodriguez et al suggest it is unlikely to have formed in the same manner as planets 57 Shortly after that Liu et al published an account of a very cold c 370 K 97 C 206 F brown dwarf orbiting another very low mass brown dwarf and noted that Given its low luminosity atypical colors and cold temperature CFBDS J1458 10B is a promising candidate for the hypothesized Y spectral class 58 In August 2011 scientists using data from NASA s Wide field Infrared Survey Explorer WISE discovered six objects that they classified as Y dwarfs with temperatures as cool as 25 C 298 K 77 F 59 60 WISE 0458 6434 is the first ultra cool brown dwarf green dot discovered by WISE The green and blue comes from infrared wavelengths mapped to visible colors WISE data has revealed hundreds of new brown dwarfs Of these fourteen are classified as cool Ys 23 One of the Y dwarfs called WISE 1828 2650 was as of August 2011 the record holder for the coldest brown dwarf emitting no visible light at all this type of object resembles free floating planets more than stars WISE 1828 2650 was initially estimated to have an atmospheric temperature cooler than 300 K 27 C 80 F 61 Its temperature has since been revised and newer estimates put it in the range of 250 to 400 K 23 to 127 C 10 to 260 F 62 In April 2014 WISE 0855 0714 was announced with a temperature profile estimated around 225 to 260 K 48 13 C 55 8 F and a mass of 3 to 10 MJ 63 It was also unusual in that its observed parallax meant a distance close to 7 2 0 7 light years from the Solar System The CatWISE catalog combines NASA s WISE and NEOWISE survey 64 It expands the number of faint sources and is therefore used to find the faintest brown dwarfs including Y dwarfs Seventeen candidate Y dwarfs were discovered by the CatWISE researchers Initial color with the Spitzer Space Telescope indicated that CW1446 is one of the reddest and coldest Y dwarfs 65 Additional data with Spitzer showed that CW1446 is the fifth reddest brown dwarf with a temperature of about 310 to 360 K 37 87 C 98 188 F at a distance of about 10 parsec 45 A search of the CatWISE catalog in 2019 revealed CWISEP J1935 1546 one of the coldest brown dwarfs with an estimated temperature of 270 to 360 K 3 87 C 26 188 F 66 In January 2020 the discovery of WISE J0830 2837 initially discovered by citizen scientists of the Backyard Worlds project was presented at the 235th meeting of the American Astronomical Society This Y dwarf is 36 5 light years distant from the Solar System and has a temperature of about 350 K 77 C 170 F 67 Role of vertical mixing Edit Major chemical pathways linking carbon monoxide and methane The short lived radicals are marked with a dot Adopted from Zahnle amp Marley 68 In the hydrogen dominated atmosphere of brown dwarfs a chemical equilibrium between carbon monoxide and methane exists Carbon monoxide reacts with hydrogen molecules and forms methane and hydroxy in this reaction The hydroxy radical might later react with hydrogen and form water molecules In the other direction of the reaction methane reacts with hydroxy and forms carbon monoxide and hydrogen The chemical reaction is tilted towards carbon monoxide at higher temperatures L dwarfs and lower pressure At lower temperatures T dwarfs and higher pressure the reaction is tilted towards methane and methane predominates at the T Y boundary Vertical mixing of the atmosphere can however cause methane to sink into lower layers of the atmosphere and carbon monoxide to rise from these lower and hotter layers The carbon monoxide is slow to react back into methane because of an energy barrier that prevents the break down of the C O bonds This forces the observable atmosphere of a brown dwarf to be in a chemical disequilibrium The L T transition is mainly defined with the transition from a carbon monoxide dominated atmosphere in L dwarfs to a methane dominated atmosphere in T dwarfs The amount of vertical mixing can therefore push the L T transition to lower or higher temperatures This becomes important for objects with modest surface gravity and extended atmospheres such as giant exoplanets This pushes the L T transition to lower temperatures for giant exoplanets For brown dwarfs this transition occurs at around 1200 K The exoplanet HR 8799c on the other hand does not show any methane while having a temperature of 1100K 68 The transition between T Y dwarfs is often defined at around 500 K due to missing spectral observations of these cold and faint objects 69 Future observations with JWST and the ELTs might improve the sample of Y dwarfs with observed spectra Y dwarfs are dominated by deep spectral features of methane water vapor and possibly absorption features of ammonia and water ice 69 Vertical mixing clouds metallicity photochemistry lightning impact shocks and metallic catalysts might influence the temperature at which the L T and T Y transition occurs 68 Secondary features Edit Brown dwarf spectral types Secondary featurespec This suffix e g L2pec stands for peculiar 70 sd This prefix e g sdL0 stands for subdwarf and indicates a low metallicity and blue color 71 b Objects with the beta b suffix e g L4b have an intermediate surface gravity 72 g Objects with the gamma g suffix e g L5g have a low surface gravity 72 red The red suffix e g L0red indicates objects without signs of youth but high dust content 73 blue The blue suffix e g L3blue indicates unusual blue near infrared colors for L dwarfs without obvious low metallicity 74 Young brown dwarfs have low surface gravities because they have larger radii and lower masses compared to the field stars of similar spectral type These sources are marked by a letter beta b for intermediate surface gravity and gamma g for low surface gravity Indication for low surface gravity are weak CaH K I and Na I lines as well as strong VO line 72 Alpha a stands for normal surface gravity and is usually dropped Sometimes an extremely low surface gravity is denoted by a delta d 74 The suffix pec stands for peculiar The peculiar suffix is still used for other features that are unusual and summarizes different properties indicative of low surface gravity subdwarfs and unresolved binaries 75 The prefix sd stands for subdwarf and only includes cool subdwarfs This prefix indicates a low metallicity and kinematic properties that are more similar to halo stars than to disk stars 71 Subdwarfs appear bluer than disk objects 76 The red suffix describes objects with red color but an older age This is not interpreted as low surface gravity but as a high dust content 73 74 The blue suffix describes objects with blue near infrared colors that cannot be explained with low metallicity Some are explained as L T binaries others are not binaries such as 2MASS J11263991 5003550 and are explained with thin and or large grained clouds 74 Spectral and atmospheric properties of brown dwarfs Edit Artist s illustration of a brown dwarf s interior structure Cloud layers at certain depths are offset as a result of layer shifting The majority of flux emitted by L and T dwarfs is in the 1 to 2 5 micrometre near infrared range Low and decreasing temperatures through the late M L and T dwarf sequence result in a rich near infrared spectrum containing a wide variety of features from relatively narrow lines of neutral atomic species to broad molecular bands all of which have different dependencies on temperature gravity and metallicity Furthermore these low temperature conditions favor condensation out of the gas state and the formation of grains Wind measured Spitzer ST Artist Concept 9 Apr 2020 77 Typical atmospheres of known brown dwarfs range in temperature from 2 200 down to 750 K 50 Compared to stars which warm themselves with steady internal fusion brown dwarfs cool quickly over time more massive dwarfs cool more slowly than less massive ones There is some evidence that the cooling of brown dwarfs slows down at the transition between spectral classes L and T about 1000 K 78 Observations of known brown dwarf candidates have revealed a pattern of brightening and dimming of infrared emissions that suggests relatively cool opaque cloud patterns obscuring a hot interior that is stirred by extreme winds The weather on such bodies is thought to be extremely strong comparable to but far exceeding Jupiter s famous storms On January 8 2013 astronomers using NASA s Hubble and Spitzer space telescopes probed the stormy atmosphere of a brown dwarf named 2MASS J22282889 4310262 creating the most detailed weather map of a brown dwarf thus far It shows wind driven planet sized clouds The new research is a stepping stone toward a better understanding not only brown dwarfs but also of the atmospheres of planets beyond the Solar System 79 In April 2020 scientists reported clocking wind speeds of 650 310 metres per second up to 1 450 miles per hour on the nearby brown dwarf 2MASS J10475385 2124234 To calculate the measurements scientists compared the rotational movement of atmospheric features as ascertained by brightness changes against the electromagnetic rotation generated by the brown dwarf s interior The results confirmed previous predictions that brown dwarfs would have high winds Scientists are hopeful that this comparison method can be used to explore the atmospheric dynamics of other brown dwarfs and extrasolar planets 80 Observational techniques Edit Brown dwarfs Teide 1 Gliese 229B and WISE 1828 2650 compared to red dwarf Gliese 229A Jupiter and our Sun Coronagraphs have recently been used to detect faint objects orbiting bright visible stars including Gliese 229B Sensitive telescopes equipped with charge coupled devices CCDs have been used to search distant star clusters for faint objects including Teide 1 Wide field searches have identified individual faint objects such as Kelu 1 30 light years away Brown dwarfs are often discovered in surveys to discover extrasolar planets Methods of detecting extrasolar planets work for brown dwarfs as well although brown dwarfs are much easier to detect Brown dwarfs can be powerful emitters of radio emission due to their strong magnetic fields Observing programs at the Arecibo Observatory and the Very Large Array have detected over a dozen such objects which are also called ultracool dwarfs because they share common magnetic properties with other objects in this class 81 The detection of radio emission from brown dwarfs permits their magnetic field strengths to be measured directly Milestones Edit 1995 First brown dwarf verified Teide 1 an M8 object in the Pleiades cluster is picked out with a CCD in the Spanish Observatory of Roque de los Muchachos of the Instituto de Astrofisica de Canarias First methane brown dwarf verified Gliese 229B is discovered orbiting red dwarf Gliese 229A 20 ly away using an adaptive optics coronagraph to sharpen images from the 60 inch 1 5 m reflecting telescope at Palomar Observatory on Southern California s Mt Palomar follow up infrared spectroscopy made with their 200 inch 5 1 m Hale telescope shows an abundance of methane 1998 First X ray emitting brown dwarf found Cha Halpha 1 an M8 object in the Chamaeleon I dark cloud is determined to be an X ray source similar to convective late type stars 15 December 1999 First X ray flare detected from a brown dwarf A team at the University of California monitoring LP 944 20 60 MJ 16 ly away via the Chandra X ray Observatory catches a 2 hour flare 82 27 July 2000 First radio emission in flare and quiescence detected from a brown dwarf A team of students at the Very Large Array detected emission from LP 944 20 83 30 April 2004 First detection of a candidate exoplanet around a brown dwarf 2M1207b discovered with the VLT and the first directly imaged exoplanet 84 20 March 2013 Discovery of the closest brown dwarf system Luhman 16 85 25 April 2014 Coldest known brown dwarf discovered WISE 0855 0714 is 7 2 light years away seventh closest system to the Sun and has a temperature between 48 to 13 C 63 Brown dwarf as an X ray source Edit Chandra image of LP 944 20 before flare and during flare X ray flares detected from brown dwarfs since 1999 suggest changing magnetic fields within them similar to those in very low mass stars With no strong central nuclear energy source the interior of a brown dwarf is in a rapid boiling or convective state When combined with the rapid rotation that most brown dwarfs exhibit convection sets up conditions for the development of a strong tangled magnetic field near the surface The flare observed by Chandra from LP 944 20 could have its origin in the turbulent magnetized hot material beneath the brown dwarf s surface A sub surface flare could conduct heat to the atmosphere allowing electric currents to flow and produce an X ray flare like a stroke of lightning The absence of X rays from LP 944 20 during the non flaring period is also a significant result It sets the lowest observational limit on steady X ray power produced by a brown dwarf and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2 800 K and becomes electrically neutral Using NASA s Chandra X ray Observatory scientists have detected X rays from a low mass brown dwarf in a multiple star system 86 This is the first time that a brown dwarf this close to its parent star s Sun like stars TWA 5A has been resolved in X rays 86 Our Chandra data show that the X rays originate from the brown dwarf s coronal plasma which is some 3 million degrees Celsius said Yohko Tsuboi of Chuo University in Tokyo 86 This brown dwarf is as bright as the Sun today in X ray light while it is fifty times less massive than the Sun said Tsuboi 86 This observation thus raises the possibility that even massive planets might emit X rays by themselves during their youth 86 Brown dwarfs as radio sources Edit The first brown dwarf that was discovered to emit radio signals was LP 944 20 which was observed based on its X ray emission Approximately 5 10 of brown dwarfs appear to have strong magnetic fields and emit radio waves and there may be as many as 40 magnetic brown dwarfs within 25 pc of the Sun based on Monte Carlo modeling and their average spatial density 87 The power of the radio emissions of brown dwarfs is roughly constant despite variations in their temperatures 81 Brown dwarfs may maintain magnetic fields of up to 6 kG in strength 88 Astronomers have estimated brown dwarf magnetospheres to span an altitude of approximately 107 m given properties of their radio emissions 89 It is unknown whether the radio emissions from brown dwarfs more closely resemble those from planets or stars Some brown dwarfs emit regular radio pulses which are sometimes interpreted as radio emission beamed from the poles but may also be beamed from active regions The regular periodic reversal of radio wave orientation may indicate that brown dwarf magnetic fields periodically reverse polarity These reversals may be the result of a brown dwarf magnetic activity cycle similar to the solar cycle 90 Binary brown dwarfs Edit Multi epoch images of brown dwarf binaries taken with the Hubble Space Telescope The binary Luhman 16 AB left is closer to the Solar System than the other examples shown here Observations of the orbit of binary systems containing brown dwarfs can be used to measure the mass of the brown dwarf In the case of 2MASSW J0746425 2000321 the secondary weighs 6 of the solar mass This measurement is called a dynamical mass 91 92 The brown dwarf system closest to the Solar System is the binary Luhman 16 It was attempted to search for planets around this system with a similar method but none were found 93 The wide binary system 2M1101AB was the first binary with a separation greater than 20 AU The discovery of the system gave definitive insights to the formation of brown dwarfs It was previously thought that wide binary brown dwarfs are not formed or at least are disrupted at ages of 1 10 Myr The existence of this system is also inconsistent with the ejection hypothesis 94 The ejection hypothesis was a proposed hypothesis in which brown dwarfs form in a multiple system but are ejected before they gain enough mass to burn hydrogen 95 More recently the wide binary W2150AB was discovered It has a similar mass ratio and binding energy as 2M1101AB but a greater age and is located in a different region of the galaxy While 2M1101AB is in a closely crowded region the binary W2150AB is in a sparsely separated field It must have survived any dynamical interactions in its natal star cluster The binary belongs also to a few L T binaries that can be easily resolved by ground based observatories The other two are SDSS J1416 13AB and Luhman 16 96 There are other interesting binary systems such as the eclipsing binary brown dwarf system 2MASS J05352184 0546085 97 Photometric studies of this system have revealed that the less massive brown dwarf in the system is hotter than its higher mass companion 98 Brown dwarfs around white dwarfs are quite rare GD 165B the prototype of the L dwarfs is one such system 99 Systems with close tidally locked brown dwarfs orbiting around white dwarfs belong to the post common envelope binaries or PCEBs Only 8 confirmed PCEBs containing a white dwarf with a brown dwarf companion are known including WD 0137 349 AB In the past history of these close white dwarf brown dwarf binaries the brown dwarf is engulfed by the star in the red giant phase Brown dwarfs with a mass lower than 20 Jupiter masses would evaporate during the engulfment 100 101 The dearth of brown dwarfs orbiting close to white dwarfs can be compared with similar observations of brown dwarfs around main sequence stars described as the brown dwarf desert 102 103 The PCEB might evolve into a cataclysmic variable star CV with the brown dwarf as the donor 104 and in the last stage of the system the binary might merge The nova CK Vulpeculae might be a result of such a white dwarf brown dwarf merger 105 106 Recent developments Edit A visualization representing a three dimensional map of brown dwarfs red dots that have been discovered within 65 light years of the Sun 107 Estimates of brown dwarf populations in the solar neighbourhood suggest that there may be as many as six stars for every brown dwarf 108 A more recent estimate from 2017 using the young massive star cluster RCW 38 concluded that the Milky Way galaxy contains between 25 and 100 billion brown dwarfs 109 Compare these numbers to the estimates of the number of stars in the Milky Way 100 to 400 billion In a study published in Aug 2017 NASA s Spitzer Space Telescope monitored infrared brightness variations in brown dwarfs caused by cloud cover of variable thickness The observations revealed large scale waves propagating in the atmospheres of brown dwarfs similarly to the atmosphere of Neptune and other Solar System giant planets These atmospheric waves modulate the thickness of the clouds and propagate with different velocities probably due to differential rotation 110 In August 2020 astronomers discovered 95 brown dwarfs near the Sun through the project Backyard Worlds Planet 9 111 Formation and evolution Edit The HH 1165 jet launched by the brown dwarf Mayrit 1701117 in the outer periphery of the sigma Orionis clusterBrown dwarfs form similarly to stars and are surrounded by protoplanetary disks 112 such as Cha 110913 773444 As of 2017 there is only one known proto brown dwarf that is connected with a large Herbig Haro object This is the brown dwarf Mayrit 1701117 which is surrounded by a pseudo disk and a Keplerian disk 113 Mayrit 1701117 launches the 0 7 light year long jet H 1165 mostly seen in ionized sulfur 114 115 Disks around brown dwarfs have been found to have many of the same features as disks around stars therefore it is expected that there will be accretion formed planets around brown dwarfs 112 Given the small mass of brown dwarf disks most planets will be terrestrial planets rather than gas giants 116 If a giant planet orbits a brown dwarf across our line of sight then because they have approximately the same diameter this would give a large signal for detection by transit 117 The accretion zone for planets around a brown dwarf is very close to the brown dwarf itself so tidal forces would have a strong effect 116 The brown dwarf Cha 110913 773444 located 500 light years away in the constellation Chamaeleon may be in the process of forming a miniature planetary system Astronomers from Pennsylvania State University have detected what they believe to be a disk of gas and dust similar to the one hypothesized to have formed the Solar System Cha 110913 773444 is the smallest brown dwarf found to date 8 MJ and if it formed a planetary system it would be the smallest known object to have one 118 Planets around brown dwarfs Edit Artist s impression of a disc of dust and gas around a brown dwarf 119 The super Jupiter planetary mass objects 2M1207b 2MASS J044144 and Oph 98 B that are orbiting brown dwarfs at large orbital distances may have formed by cloud collapse rather than accretion and so may be sub brown dwarfs rather than planets which is inferred from relatively large masses and large orbits The first discovery of a low mass companion orbiting a brown dwarf ChaHa8 at a small orbital distance using the radial velocity technique paved the way for the detection of planets around brown dwarfs on orbits of a few AU or smaller 120 121 However with a mass ratio between the companion and primary in ChaHa8 of about 0 3 this system rather resembles a binary star Then in 2008 the first planetary mass companion in a relatively small orbit MOA 2007 BLG 192Lb was discovered orbiting a brown dwarf 122 Planets around brown dwarfs are likely to be carbon planets depleted of water 123 A 2017 study based upon observations with Spitzer estimates that 175 brown dwarfs need to be monitored in order to guarantee 95 at least one detection of a planet 124 Habitability Edit Habitability for hypothetical planets orbiting brown dwarfs has been studied Computer models suggesting conditions for these bodies to have habitable planets are very stringent the habitable zone being narrow close T dwarf 0 005 AU and decreasing with time due to the cooling of the brown dwarf they fuse for at most 10 million years The orbits there would have to be of extremely low eccentricity on the order of 10 to the minus 6 to avoid strong tidal forces that would trigger a runaway greenhouse effect on the planets rendering them uninhabitable There would also be no moons 125 Superlative brown dwarfs EditMain article List of brown dwarfs In 1984 it was postulated by some astronomers that the Sun may be orbited by an undetected brown dwarf sometimes referred to as Nemesis that could interact with the Oort cloud just as passing stars can However this hypothesis has fallen out of favor 126 Table of firsts Edit Record Name Spectral type RA Dec Constellation NotesFirst discovered Teide 1 Pleiades Open Star Cluster M8 3h47m18 0s 24 22 31 Taurus Imaged in 1989 and 1994First imaged with coronography Gliese 229 B T6 5 06h10m34 62s 21 51 52 1 Lepus Discovered 1994First with planemo 2M1207 M8 12h07m33 47s 39 32 54 0 Centaurus Planet discovered in 2004First with a dust diskFirst with bipolar outflow Rho Oph 102 SIMBAD GY92 102 16 26 42 758 24 41 22 24 Ophiuchus partly resolved outflow 127 First with large scale Herbig Haro object Mayrit 1701117 Herbig Haro object HH 1165 proto BD 05 40 25 799 02 48 55 42 Orion projected length of the Herbig Haro object 0 8 light years 0 26 pc 115 First field type solitary Teide 1 M8 3h47m18 0s 24 22 31 Taurus 1995First as a companion to a normal star Gliese 229 B T6 5 06h10m34 62s 21 51 52 1 Lepus 1995First spectroscopic binary brown dwarf PPL 15 A B 128 M6 5 Taurus Basri and Martin 1999First eclipsing binary brown dwarf 2M0535 05 129 98 M6 5 Orion Stassun 2006 2007 distance 450 pc First binary brown dwarf of T Type Epsilon Indi Ba Bb 130 T1 T6 Indus Distance 3 626pcFirst trinary brown dwarf DENIS P J020529 0 115925 A B C L5 L8 and T0 02h05m29 40s 11 59 29 7 Cetus Delfosse et al 1997 131 First halo brown dwarf 2MASS J05325346 8246465 sdL7 05h32m53 46s 82 46 46 5 Gemini Burgasser et al 2003 132 First with late M spectrum Teide 1 M8 3h47m18 0s 24 22 31 Taurus 1995First with L spectrum GD 165B L4 14h 24m 39 144s 09 17 13 98 Bootes 1988First with T spectrum Gliese 229 B T6 5 06h10m34 62s 21 51 52 1 Lepus 1995Latest T spectrum ULAS J003402 77 005206 7 T9 54 Cetus 2007First with Y spectrum CFBDS0059 53 Y0 00h 59m 10 83s 01 14 01 3 Cetus 2008 this is also classified as a T9 dwarf due to its close resemblance to other T dwarfs 54 First X ray emitting ChaHa1 M8 Chamaeleon 1998First X ray flare LP 944 20 M9V 03h39m35 22s 35 25 44 1 Fornax 1999First radio emission in flare and quiescence LP 944 20 M9V 03h39m35 22s 35 25 44 1 Fornax 2000 83 First potential brown dwarf auroras discovered LSR J1835 3259 M8 5 Lyra 2015First detection of differential rotation in a brown dwarf TVLM 513 46546 M9 15h01m08 3s 22 50 02 Bootes Equator rotates faster than poles by 0 022 radians day 133 First confirmed brown dwarf to have survived the primary s red giant phase WD 0137 349 B 134 L8 01h 39m 42 847s 34 42 39 32 Sculptor constellation Table of extremes Edit This list is incomplete you can help by adding missing items August 2008 Record Name Spectral type RA Dec Constellation NotesOldest COCONUTS 1B T4 03 55 56 871 45 25 46 83 Perseus one of the few examples with a good age estimate 7 3 2 8 1 6 billion years 48 Youngest 2MASS J05413280 0151272 M8 5 05h 41m 32 801s 01 51 27 20 Orion One brown dwarf member of the about 0 5 Myr old Flame Nebula 20 9 MJ object 135 Most massive SDSS J010448 46 153501 8 136 usdL1 5 01h04m48 46s 15 35 01 8 Pisces distance is 180 290 pc mass is 88 5 91 7 MJ Transitional brown dwarfs Metal richMetal poor SDSS J010448 46 153501 8 136 usdL1 5 01h04m48 46s 15 35 01 8 Pisces distance is 180 290 pc metallicity is 0 004 ZSol Transitional brown dwarfs Least massive OTS 44 M9 5 11h 10m 11 5s 76 32 13 Chamaeleon Has a mass range of 11 5 15 MJ distance is 550 lyLargestSmallestFastest rotating 2MASS J03480772 6022270 T7 03h48m07 72s 60 22 27 1 Reticulum Rotational period of 1 080 0 004 0 005 137 Farthest KMT 2016 BLG 2142 b 17h 52m 27 0s 29 23 04 Sagittarius KMT 2016 BLG 2142 b microlensing 138 has a distance of 5 850 to 8 020 parsec Could also be massive gas giant Nearest Luhman 16 AB L7 5 T0 5 1 10h 49m 18 723s 53 19 09 86 Vela Distance 6 5 lyBrightestDimmest L 97 3B Y1 08h 06m 53 736s 66 18 16 74 Volans jmag 25 42HottestCoolest WISE 0855 0714 63 Y4 08h 55m 10 83s 07 14 42 5 Hydra Temperature 48 to 13 CCoolest radio flaring 2MASSI J10475385 2124234 T6 5 10h47m53 85s 21 24 23 4 Leo 900 K brown dwarf with 2 7 mJy bursts 139 Most dense TOI 569b 140 Transiting brown dwarf TOI 569b has 64 1 MJ with a diameter 0 79 0 02 times that of Jupiter Density is 171 3g cm3 Least denseGallery Edit Brown dwarf illustration 141 See also EditFusor astronomy Brown dwarf desert Theorized range of orbits around a star within which brown dwarfs cannot exist as companion objects Blue dwarf red dwarf stage Hypothetical class of star that develops from a red dwarf Dark matter Hypothetical form of matter Exoplanet Planet outside the Solar System StellificationReferences Edit Sorahana Satoko Yamamura Issei Murakami Hiroshi 2013 On the Radii of Brown Dwarfs Measured with AKARI Near infrared Spectroscopy The Astrophysical Journal 767 1 77 arXiv 1304 1259 Bibcode 2013ApJ 767 77S doi 10 1088 0004 637X 767 1 77 We find that the brown dwarf radius ranges between 0 64 1 13 RJ with an average radius of 0 83 RJ Boss Alan McDowell Tina April 3 2001 Are They Planets or What Untitled Document Carnegie Institution of Washington Archived from the original on September 28 2006 Retrieved March 31 2022 a b c Wethington Nicholos October 6 2008 Dense Exoplanet Creates Classification Calamity Universe Today Retrieved March 31 2022 a b c d Burgasser Adam J June 2008 Brown dwarfs Failed stars super Jupiters PDF Physics Today Cambridge MA Massachusetts Institute of Technology 61 6 70 71 Bibcode 2008PhT 61f 70B doi 10 1063 1 2947658 Archived from the original PDF on May 8 2013 Retrieved March 31 2022 via American Institute of Physics Springer Cham 2014 Joergens Viki ed 50 Years of Brown Dwarfs Astrophysics and Space Science Library Vol 401 SpringerLink XI 168 doi 10 1007 978 3 319 01162 2 eISSN 2214 7985 ISBN 978 3 319 01162 2 ISSN 0067 0057 Retrieved March 31 2022 a b Cain Fraser January 6 2009 If Brown Isn t a Color What Color are Brown Dwarfs Retrieved 24 September 2013 Burrows Adam Hubbard William B Lunine Jonathan I Liebert James 2001 The Theory of Brown Dwarfs and Extrasolar Giant Planets Reviews of Modern Physics 73 3 719 765 arXiv astro ph 0103383 Bibcode 2001RvMP 73 719B doi 10 1103 RevModPhys 73 719 S2CID 204927572 O Neill Ian 13 September 2011 Violent Storms Rage on Nearby Brown Dwarf Seeker com Kumar Shiv S 1962 Study of Degeneracy in Very Light Stars Astronomical Journal 67 579 Bibcode 1962AJ 67S 579K doi 10 1086 108658 Tarter Jill 2014 Brown is Not a Color Introduction of the Term Brown Dwarf in Joergens Viki ed 50 Years of Brown Dwarfs From Prediction to Discovery to Forefront of Research Astrophysics and Space Science Library vol 401 Springer pp 19 24 doi 10 1007 978 3 319 01162 2 3 ISBN 978 3 319 01162 2 Croswell Ken 1999 Planet Quest The Epic Discovery of Alien Solar Systems Oxford University Press pp 118 119 ISBN 978 0 192 88083 3 When will the Sun become a black dwarf Astronomy com April 10 2020 Retrieved 2022 05 02 Kumar Shiv S 1963 The Structure of Stars of Very Low Mass Astrophysical Journal 137 1121 Bibcode 1963ApJ 137 1121K doi 10 1086 147589 Hayashi Chushiro Nakano Takenori 1963 Evolution of Stars of Small Masses in the Pre Main Sequence Stages Progress of Theoretical Physics 30 4 460 474 Bibcode 1963PThPh 30 460H doi 10 1143 PTP 30 460 Nakano Takenori 2014 Pre main Sequence Evolution and the Hydrogen Burning Minimum Mass in Joergens Viki ed 50 Years of Brown Dwarfs From Prediction to Discovery to Forefront of Research Astrophysics and Space Science Library vol 401 Springer pp 5 17 doi 10 1007 978 3 319 01162 2 2 ISBN 978 3 319 01162 2 S2CID 73521636 Martin Eduardo L Basri Gibor Delfosse Xavier Forveille Thierry 1997 Keck HIRES spectra of the brown dwarf DENIS P J1228 2 1547 Astronomy and Astrophysics 327 L29 L32 Bibcode 1997A amp A 327L 29M Kirkpatrick J Davy Reid I Neill Liebert James Cutri Roc M Nelson Brant Beichmann Charles A Dahn Conard C Monet David G Gizis John E Skrutskie Michael F 1999 Dwarfs Cooler than M The Definition of Spectral Type L Using Discoveries from the 2 Micron All Sky Survey 2MASS PDF The Astrophysical Journal 519 2 802 833 Bibcode 1999ApJ 519 802K doi 10 1086 307414 S2CID 73569208 Astronomers Announce First Clear Evidence of a Brown Dwarf STScI Retrieved 2019 10 23 Instituto de Astrofisica de Canarias IAC Iac es Retrieved 2013 03 16 Rebolo Rafael 2014 Teide 1 and the Discovery of Brown Dwarfs in Joergens Viki ed 50 Years of Brown Dwarfs From Prediction to Discovery to Forefront of Research Astrophysics and Space Science Library vol 401 Springer pp 25 50 doi 10 1007 978 3 319 01162 2 4 ISBN 978 3 319 01162 2 Rebolo Rafael Zapatero Osorio Maria Rosa Martin Eduardo L September 1995 Discovery of a brown dwarf in the Pleiades star cluster Nature 377 6545 129 131 Bibcode 1995Natur 377 129R doi 10 1038 377129a0 S2CID 28029538 Leech Kieron Altieri Bruno Metcalfe Liam Martin Eduardo L Rebolo Rafael Zapatero Osorio Maria Rosa Laureijs Rene J Prusti Timo Salama Alberto Siebenmorgen Ralf Claes Peter Trams Norman 2000 Mid IR Observations of the Pleiades Brown Dwarfs Teide 1 amp Calar 3 ASP Conference Series 212 82 87 Bibcode 2000ASPC 212 82L a b c d Kirkpatrick J Davy Burgasser Adam J 6 November 2012 Photometry spectroscopy and astrometry of M L and T dwarfs DwarfArchives org Pasadena CA California Institute of Technology Retrieved 2012 12 28 M 536 L 918 T 355 Y 14 McCaughrean Mark J Close Laird M Scholz Ralf Dieter Lenzen Rainer Biller Beth A Brandner Wolfgang Hartung Markus Lodieu Nicolas January 2004 Epsilon Indi Ba Bb the nearest binary brown dwarf Astronomy amp Astrophysics 413 3 1029 1036 arXiv astro ph 0309256 doi 10 1051 0004 6361 20034292 S2CID 15407249 a b Forbes John C Loeb Abraham February 2019 On the Existence of Brown Dwarfs More Massive than the Hydrogen Burning Limit The Astrophysical Journal 871 2 11 arXiv 1805 12143 Bibcode 2019ApJ 871 227F doi 10 3847 1538 4357 aafac8 S2CID 119059288 227 Burrows Adam Hubbard W B Lunine J I Liebert James July 2001 The theory of brown dwarfs and extrasolar giant planets Reviews of Modern Physics 73 3 719 765 arXiv astro ph 0103383 Bibcode 2001RvMP 73 719B doi 10 1103 RevModPhys 73 719 S2CID 204927572 Hence the HBMM at solar metallicity and Ya 50 25 is 0 07 0 074 M while the HBMM at zero metallicity is 0 092 M Kulkarni Shrinivas R 30 May 1997 Brown Dwarfs A Possible Missing Link Between Stars and Planets Science 276 5317 1350 1354 Bibcode 1997Sci 276 1350K doi 10 1126 science 276 5317 1350 Biller Beth A Crossfield Ian J M Mancini Luigi Ciceri Simona Southworth John Kopytova Taisiya G Bonnefoy Mickael Deacon Niall R Schlieder Joshua E Buenzli Esther Brandner Wolfgang Allard France Homeier Derek Freytag Bernd Bailer Jones Coryn A L Greiner Jochen Henning Thomas Goldman Bertrand 6 November 2013 Weather on the Nearest Brown Dwarfs Resolved Simultaneous Multi Wavelength Variability Monitoring of WISE J104915 57 531906 1AB The Astrophysical Journal Letters 778 1 L10 arXiv 1310 5144 Bibcode 2013ApJ 778L 10B doi 10 1088 2041 8205 778 1 l10 S2CID 56107487 Basri Gibor Brown Michael E 2006 08 20 Planetesimals to Brown Dwarfs What is a Planet Annual Review of Earth and Planetary Sciences 34 2006 193 216 arXiv astro ph 0608417 Bibcode 2006AREPS 34 193B doi 10 1146 annurev earth 34 031405 125058 S2CID 119338327 Chen Jingjing Kipping David 2016 Probabilistic Forecasting of the Masses and Radii of Other Worlds The Astrophysical Journal 834 1 17 arXiv 1603 08614 doi 10 3847 1538 4357 834 1 17 S2CID 119114880 Retrieved 27 July 2021 The Jovian Planets Uranus and Neptune Archived from the original on 2012 01 18 Retrieved 2013 03 15 Cool Cosmos Planets and Moons Archived from the original on 2019 02 21 Retrieved 2019 02 11 Working Group on Extrasolar Planets Definition of a Planet IAU position statement 2003 02 28 Archived from the original on 2014 12 16 Retrieved 2014 04 28 Bodenheimer Peter D Angelo Gennaro Lissauer Jack J Fortney Jonathan J Saumon Didier 2013 Deuterium Burning in Massive Giant Planets and Low mass Brown Dwarfs Formed by Core nucleated Accretion The Astrophysical Journal 770 2 120 13 pp arXiv 1305 0980 Bibcode 2013ApJ 770 120B doi 10 1088 0004 637X 770 2 120 S2CID 118553341 Spiegel David S Burrows Adam Milson John A 2011 The Deuterium Burning Mass Limit for Brown Dwarfs and Giant Planets The Astrophysical Journal 727 1 57 arXiv 1008 5150 Bibcode 2011ApJ 727 57S doi 10 1088 0004 637X 727 1 57 S2CID 118513110 Schneider Jean Dedieu Cyril Le Sidaner Pierre Savalle Renaud Zolotukhin Ivan 2011 Defining and cataloging exoplanets The exoplanet eu database Astronomy amp Astrophysics 532 79 A79 arXiv 1106 0586 Bibcode 2011A amp A 532A 79S doi 10 1051 0004 6361 201116713 S2CID 55994657 Schneider Jean July 2016 Exoplanets versus brown dwarfs the CoRoT view and the future The CoRoT Legacy Book p 157 arXiv 1604 00917 doi 10 1051 978 2 7598 1876 1 c038 ISBN 978 2 7598 1876 1 S2CID 118434022 Hatzes Artie P Rauer Heike 2015 A Definition for Giant Planets Based on the Mass Density Relationship The Astrophysical Journal 810 2 L25 arXiv 1506 05097 Bibcode 2015ApJ 810L 25H doi 10 1088 2041 8205 810 2 L25 S2CID 119111221 Wright Jason T Fakhouri Onsi Marcy Geoffrey W Han Eunkyu Feng Y Katherina Johnson John Asher Howard Andrew W Fischer Debra A Valenti Jeff A Anderson Jay Piskunov Nikolai 2010 The Exoplanet Orbit Database Publications of the Astronomical Society of the Pacific 123 902 412 422 arXiv 1012 5676 Bibcode 2011PASP 123 412W doi 10 1086 659427 S2CID 51769219 Exoplanet Criteria for Inclusion in the Archive NASA Exoplanet Archive Working Group on Extrasolar Planets Definition of a Planet Archived 2012 07 02 at the Wayback Machine Position statement on the definition of a planet IAU Delorme Philippe Gagne Jonathan Malo Lison Reyle Celine Artigau Etienne Albert Loic Forveille Thierry Delfosse Xavier Allard France Homeier Derek December 2012 CFBDSIR2149 0403 a 4 7 Jupiter mass free floating planet in the young moving group AB Doradus Astronomy amp Astrophysics 548 A26 arXiv 1210 0305 Bibcode 2012A amp A 548A 26D doi 10 1051 0004 6361 201219984 S2CID 50935950 Luhman Kevin L 21 April 2014 Discovery of a 250 K Brown Dwarf at 2 pc from the Sun The Astrophysical Journal Letters 786 2 L18 arXiv 1404 6501 Bibcode 2014ApJ 786L 18L doi 10 1088 2041 8205 786 2 L18 S2CID 119102654 Saumon Didier Marley Mark S December 2008 The Evolution of L and T Dwarfs in Color Magnitude Diagrams Astrophysical Journal 689 2 1327 1344 arXiv 0808 2611 Bibcode 2008ApJ 689 1327S doi 10 1086 592734 ISSN 0004 637X S2CID 15981010 a b Marocco Federico Kirkpatrick J Davy Meisner Aaron M Caselden Dan Eisenhardt Peter R M Cushing Michael C Faherty Jacqueline K Gelino Christopher R Wright Edward L 2020 Improved infrared photometry and a preliminary parallax measurement for the extremely cold brown dwarf CWISEP J144606 62 231717 8 The Astrophysical Journal 888 2 L19 arXiv 1912 07692 Bibcode 2020ApJ 888L 19M doi 10 3847 2041 8213 ab6201 S2CID 209386563 Filippazzo Joseph C Rice Emily L Faherty Jacqueline K Cruz Kelle L Van Gordon Mollie M Looper Dagny L September 2015 Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime Astrophysical Journal 810 2 158 arXiv 1508 01767 Bibcode 2015ApJ 810 158F doi 10 1088 0004 637X 810 2 158 ISSN 0004 637X S2CID 89611607 Mohanty Subhanjoy Jayawardhana Ray Huelamo Nuria Mamajek Eric March 2007 The Planetary Mass Companion 2MASS 1207 3932B Temperature Mass and Evidence for an Edge on Disk Astrophysical Journal 657 2 1064 1091 arXiv astro ph 0610550 Bibcode 2007ApJ 657 1064M doi 10 1086 510877 ISSN 0004 637X S2CID 17326111 a b Zhang Zhoujian Liu Michael C Hermes James J Magnier Eugene A Marley Mark S Tremblay Pier Emmanuel Tucker Michael A Do Aaron Payne Anna V Shappee Benjamin J February 2020 COol Companions ON Ultrawide orbiTS COCONUTS I A High Gravity T4 Benchmark around an Old White Dwarf and A Re Examination of the Surface Gravity Dependence of the L T Transition The Astrophysical Journal 891 2 171 arXiv 2002 05723 Bibcode 2020ApJ 891 171Z doi 10 3847 1538 4357 ab765c S2CID 211126544 Smart Richard L Bucciarelli Beatrice Jones Hugh R A Marocco Federico Andrei Alexandre Humberto Goldman Bertrand Mendez Rene A d Avila Victor de A Burningham Ben Camargo Julio Ignacio Bueno de Crosta Maria Teresa Dapra Mario Jenkins James S Lachaume Regis Lattanzi Mario G Penna Jucira L Pinfield David J da Silva Neto Dario Nepomuceno Sozzetti Alessandro Vecchiato Alberto December 2018 Parallaxes of Southern Extremely Cool objects III 118 L and T dwarfs MNRAS 481 3 3548 3562 arXiv 1811 00672 Bibcode 2018MNRAS 481 3548S doi 10 1093 mnras sty2520 ISSN 0035 8711 S2CID 119390019 a b Burrows Adam Hubbard William B Lunine Jonathan I Liebert James 2001 The theory of brown dwarfs and extrasolar giant planets Reviews of Modern Physics 73 3 719 765 arXiv astro ph 0103383 Bibcode 2001RvMP 73 719B doi 10 1103 RevModPhys 73 719 S2CID 204927572 An Artist s View of Brown Dwarf Types Archived 2011 11 17 at the Wayback Machine a b c d Leggett Sandy K Cushing Michael C Saumon Didier Marley Mark S Roellig Thomas L Warren Stephen J Burningham Ben Jones Hugh R A Kirkpatrick J Davy Lodieu Nicolas Lucas Philip W Mainzer Amy K Martin Eduardo L McCaughrean Mark J Pinfield David J Sloan Gregory C Smart Richard L Tamura Motohide Van Cleve Jeffrey 2009 The Physical Properties of Four 600 K T Dwarfs The Astrophysical Journal 695 2 1517 1526 arXiv 0901 4093 Bibcode 2009ApJ 695 1517L doi 10 1088 0004 637X 695 2 1517 S2CID 44050900 a b Delorme Philippe Delfosse Xavier Albert Loic Artigau Etienne Forveille Thierry Reyle Celine Allard France Homeier Derek Robin Annie C Willott Chris J Liu Michael C Dupuy Trent J 2008 CFBDS J005910 90 011401 3 Reaching the T Y brown dwarf transition Astronomy and Astrophysics 482 3 961 971 arXiv 0802 4387 Bibcode 2008A amp A 482 961D doi 10 1051 0004 6361 20079317 S2CID 847552 a b c Burningham Ben Pinfield David J Leggett Sandy K Tamura Motohide Lucas Philip W Homeier Derek Day Jones Avril Jones Hugh R A Clarke J R A Ishii Miki Kuzuhara Masayuki Lodieu Nicolas Zapatero Osorio Maria Rosa Venemans Bram Pieter Mortlock Daniel J Barrado y Navascues David Martin Eduardo L Magazzu Antonio 2008 Exploring the substellar temperature regime down to 550K Monthly Notices of the Royal Astronomical Society 391 1 320 333 arXiv 0806 0067 Bibcode 2008MNRAS 391 320B doi 10 1111 j 1365 2966 2008 13885 x S2CID 1438322 Eisenhardt Peter R M Griffith Roger L Stern Daniel Wright Edward L Ashby Matthew L N Brodwin Mark Brown Michael J I Bussmann R S Dey Arjun Ghez Andrea Mia Glikman Eilat Gonzalez Anthony H Kirkpatrick J Davy Konopacky Quinn Mainzer Amy Vollbach David Wright Shelley A 2010 Ultracool Field Brown Dwarf Candidates Selected at 4 5 microns The Astronomical Journal 139 6 2455 arXiv 1004 1436 Bibcode 2010AJ 139 2455E doi 10 1088 0004 6256 139 6 2455 S2CID 2019463 Luhman Kevin L Burgasser Adam J Bochanski John J 20 March 2011 Discovery of a candidate for the coolest known brown dwarf The Astrophysical Journal Letters 730 1 L9 arXiv 1102 5411 Bibcode 2011ApJ 730L 9L doi 10 1088 2041 8205 730 1 L9 S2CID 54666396 Rodriguez David R Zuckerman Benjamin Melis Carl Song Inseok 10 May 2011 The ultra cool brown dwarf companion of WD 0806 661B age mass and formation mechanism The Astrophysical Journal 732 2 L29 arXiv 1103 3544 Bibcode 2011ApJ 732L 29R doi 10 1088 2041 8205 732 2 L29 S2CID 118382542 Liu Michael C Delorme Philippe Dupuy Trent J Bowler Brendan P Albert Loic Artigau Etienne Reyle Celine Forveille Thierry Delfosse Xavier 28 Feb 2011 CFBDSIR J1458 1013B A Very Cold gt T10 Brown Dwarf in a Binary System The Astrophysical Journal 740 2 108 arXiv 1103 0014 Bibcode 2011ApJ 740 108L doi 10 1088 0004 637X 740 2 108 S2CID 118344589 Plait Phil 24 August 2011 WISE finds coolest brown dwarfs ever seen Discover Magazine Clavin Whitney 8 June 2012 WISE Finds Few Brown Dwarfs Close To Home NASA Morse Jon Discovered Stars as Cool as the Human Body Archived from the original on 7 October 2011 Retrieved 24 August 2011 Beichman Charles A Gelino Christopher R Kirkpatrick J Davy Barman Travis S Marsh Kenneth A Cushing Michael C Wright Edward L 2013 The Coldest Brown Dwarf or Free floating Planet The Y Dwarf WISE 1828 2650 The Astrophysical Journal 764 1 101 arXiv 1301 1669 Bibcode 2013ApJ 764 101B doi 10 1088 0004 637X 764 1 101 S2CID 118575478 a b c Clavin Whitney Harrington J D 25 April 2014 NASA s Spitzer and WISE Telescopes Find Close Cold Neighbor of Sun NASA gov Archived from the original on 26 April 2014 Eisenhardt Peter R M Marocco Federico Fowler John W Meisner Aaron M Kirkpatrick J Davy Garcia Nelson Jarrett Thomas H Koontz Renata Marchese Elijah J Stanford S Adam Caselden Dan 2020 The CatWISE Preliminary Catalog Motions from WISE and NEOWISE Data The Astrophysical Journal Supplement Series 247 2 69 arXiv 1908 08902 Bibcode 2020ApJS 247 69E doi 10 3847 1538 4365 ab7f2a S2CID 201645245 Meisner Aaron M Caselden Dan Kirkpatrick J Davy Marocco Federico Gelino Christopher R Cushing Michael C Eisenhardt Peter R M Wright Edward L Faherty Jacqueline K Koontz Renata Marchese Elijah J 2020 Expanding the Y Dwarf Census with Spitzer Follow up of the Coldest CatWISE Solar Neighborhood Discoveries The Astrophysical Journal 889 2 74 arXiv 1911 12372 Bibcode 2020ApJ 889 74M doi 10 3847 1538 4357 ab6215 S2CID 208513044 Marocco Federico Caselden Dan Meisner Aaron M Kirkpatrick J Davy Wright Edward L Faherty Jacqueline K Gelino Christopher R Eisenhardt Peter R M Fowler John W Cushing Michael C Cutri Roc M Garcia Nelson Jarrett Thomas H Koontz Renata Mainzer Amanda Marchese Elijah J Mobasher Bahram Schlegel David J Stern Daniel Teplitz Harry I 2019 CWISEP J193518 59 154620 3 An Extremely Cold Brown Dwarf in the Solar Neighborhood Discovered with CatWISE The Astrophysical Journal 881 1 17 arXiv 1906 08913 Bibcode 2019ApJ 881 17M doi 10 3847 1538 4357 ab2bf0 S2CID 195316522 Bardalez Gagliuffi Daniella C Faherty Jacqueline K Backyard Worlds Planet 9 Citizen Science Collaboration Schneider Adam C Meisner Aaron M Caselden Dan Colin Guillaume Goodman Sam Kirkpatrick J Davy Kuchner Marc J Gagne Jonathan Logsdon Sarah E Burgasser Adam J Allers Katelyn N Debes John H Wisniewski John January 2020 WISE J0830 2837 the first Y dwarf from Backyard Worlds Planet 9 AAS 52 132 06 Bibcode 2020AAS 23513206B a b c Zahnle Kevin J Marley Mark S 2014 12 01 Methane Carbon Monoxide and Ammonia in Brown Dwarfs and Self Luminous Giant Planets The Astrophysical Journal 797 1 41 arXiv 1408 6283 Bibcode 2014ApJ 797 41Z doi 10 1088 0004 637X 797 1 41 ISSN 0004 637X S2CID 118509317 a b Bardalez Gagliuffi Daniella C Faherty Jacqueline K Schneider Adam C Meisner Aaron Caselden Dan Colin Guillaume Goodman Sam Kirkpatrick J Davy Kuchner Marc Gagne Jonathan Logsdon Sarah E Burgasser Adam J Allers Katelyn Debes John Wisniewski John 2020 06 01 WISEA J083011 95 283716 0 A Missing Link Planetary mass Object The Astrophysical Journal 895 2 145 arXiv 2004 12829 Bibcode 2020ApJ 895 145B doi 10 3847 1538 4357 ab8d25 ISSN 0004 637X S2CID 216553879 Spectral type codes simbad u strasbg fr Retrieved 2020 03 06 a b Burningham Ben Smith Leigh Cardoso Catia V Lucas Philip W Burgasser Adam J Jones Hugh R A Smart Richard L May 2014 The discovery of a T6 5 subdwarf Monthly Notices of the Royal Astronomical Society 440 1 359 364 arXiv 1401 5982 Bibcode 2014MNRAS 440 359B doi 10 1093 mnras stu184 ISSN 0035 8711 S2CID 119283917 a b c Cruz Kelle L Kirkpatrick J Davy Burgasser Adam J February 2009 Young L Dwarfs Identified in the Field A Preliminary Low Gravity Optical Spectral Sequence from L0 to L5 The Astronomical Journal 137 2 3345 3357 arXiv 0812 0364 Bibcode 2009AJ 137 3345C doi 10 1088 0004 6256 137 2 3345 ISSN 0004 6256 S2CID 15376964 a b Looper Dagny L Kirkpatrick J Davy Cutri Roc M Barman Travis Burgasser Adam J Cushing Michael C Roellig Thomas McGovern Mark R McLean Ian S Rice Emily Swift Brandon J October 2008 Discovery of Two Nearby Peculiar L Dwarfs from the 2MASS Proper Motion Survey Young or Metal Rich Astrophysical Journal 686 1 528 541 arXiv 0806 1059 Bibcode 2008ApJ 686 528L doi 10 1086 591025 ISSN 0004 637X S2CID 18381182 a b c d Kirkpatrick J Davy Looper Dagny L Burgasser Adam J Schurr Steven D Cutri Roc M Cushing Michael C Cruz Kelle L Sweet Anne C Knapp Gillian R Barman Travis S Bochanski John J September 2010 Discoveries from a Near infrared Proper Motion Survey Using Multi epoch Two Micron All Sky Survey Data Astrophysical Journal Supplement Series 190 1 100 146 arXiv 1008 3591 Bibcode 2010ApJS 190 100K doi 10 1088 0067 0049 190 1 100 ISSN 0067 0049 S2CID 118435904 Faherty Jacqueline K Riedel Adric R Cruz Kelle L Gagne Jonathan Filippazzo Joseph C Lambrides Erini Fica Haley Weinberger Alycia Thorstensen John R Tinney Chris G Baldassare Vivienne July 2016 Population Properties of Brown Dwarf Analogs to Exoplanets Astrophysical Journal Supplement Series 225 1 10 arXiv 1605 07927 Bibcode 2016ApJS 225 10F doi 10 3847 0067 0049 225 1 10 ISSN 0067 0049 S2CID 118446190 Reid Neill Colour magnitude data www stsci edu Retrieved 2020 03 06 National Radio Astronomy Observatory 9 April 2020 Astronomers measure wind speed on a brown dwarf Atmosphere interior rotating at different speeds EurekAlert Retrieved 10 April 2020 Chen Minghan Li Yiting Brandt Timothy D Dupuy Trent J Cardoso Catia V McCaughrean Mark J 2022 Precise Dynamical Masses of e Indi Ba and Bb Evidence of Slowed Cooling at the L T Transition The Astronomical Journal 163 6 288 arXiv 2205 08077 Bibcode 2022AJ 163 288C doi 10 3847 1538 3881 ac66d2 S2CID 248834536 NASA Space Telescopes See Weather Patterns in Brown Dwarf Hubblesite NASA Archived from the original on 2 April 2014 Retrieved 8 January 2013 Astronomers Clock High Winds on Object Outside Our Solar System CNN com CNN 9 April 2020 Retrieved 11 April 2020 a b Route Matthew Wolszczan Alexander 20 October 2016 The Second Arecibo Search for 5 GHz Radio Flares from Ultracool Dwarfs The Astrophysical Journal 830 2 85 arXiv 1608 02480 Bibcode 2016ApJ 830 85R doi 10 3847 0004 637X 830 2 85 S2CID 119279978 Rutledge Robert E Basri Gibor Martin Eduardo L Bildsten Lars 1 August 2000 Chandra Detection of an X Ray Flare from the Brown Dwarf LP 944 20 The Astrophysical Journal 538 2 L141 L144 arXiv astro ph 0005559 Bibcode 2000ApJ 538L 141R doi 10 1086 312817 S2CID 17800872 a b Berger Edo Ball Steven Becker Kate M Clarke Melanie Frail Dale A Fukuda Therese A Hoffman Ian M Mellon Richard Momjian Emmanuel Murphy Nathanial W Teng Stacey H Woodruff Timothy Zauderer B Ashley Zavala Robert T 2001 03 15 Discovery of radio emission from the brown dwarf LP944 20 Nature Submitted manuscript 410 6826 338 340 arXiv astro ph 0102301 Bibcode 2001Natur 410 338B doi 10 1038 35066514 PMID 11268202 S2CID 4411256 Archived from the original on 2021 04 27 Chauvin Gael Zuckerman Ben Lagrange Anne Marie Yes it is the Image of an Exoplanet Astronomers Confirm the First Image of a Planet Outside of Our Solar System Press release European Southern Observatory Retrieved 2020 02 09 Luhman Kevin L April 2013 Discovery of a Binary Brown Dwarf at 2 pc from the Sun Astrophysical Journal Letters 767 1 L1 arXiv 1303 2401 Bibcode 2013ApJ 767L 1L doi 10 1088 2041 8205 767 1 L1 ISSN 0004 637X S2CID 8419422 a b c d e X rays from a Brown Dwarf s Corona April 14 2003 Archived from the original on December 30 2010 Retrieved March 19 2010 Route Matthew 10 August 2017 Radio flaring Ultracool Dwarf Population Synthesis The Astrophysical Journal 845 1 66 arXiv 1707 02212 Bibcode 2017ApJ 845 66R doi 10 3847 1538 4357 aa7ede S2CID 118895524 Kao Melodie M Hallinan Gregg Pineda J Sebastian Stevenson David Burgasser Adam J 31 July 2018 The Strongest Magnetic Fields on the Coolest Brown Dwarfs The Astrophysical Journal Supplement Series 237 2 25 arXiv 1808 02485 Bibcode 2018ApJS 237 25K doi 10 3847 1538 4365 aac2d5 S2CID 118898602 Route Matthew 10 July 2017 Is WISEP J060738 65 242953 4 Really A Magnetically Active Pole on L Dwarf The Astrophysical Journal 843 2 115 arXiv 1706 03010 Bibcode 2017ApJ 843 115R doi 10 3847 1538 4357 aa78ab S2CID 119056418 Route Matthew 20 October 2016 The Discovery of Solar like Activity Cycles Beyond the End of the Main Sequence The Astrophysical Journal Letters 830 2 L27 arXiv 1609 07761 Bibcode 2016ApJ 830L 27R doi 10 3847 2041 8205 830 2 L27 S2CID 119111063 Bouy Herve Weighing Ultra Cool Stars Large Ground Based Telescopes and Hubble Team Up to Perform First Direct Brown Dwarf Mass Measurement Press release European Southern Observatory Retrieved 2019 12 11 Bouy Herve Duchene Gaspard Kohler Rainer Brandner Wolfgang Bouvier Jerome Martin Eduardo L Ghez Andrea Mia Delfosse Xavier Forveille Thierry Allard France Baraffe Isabelle Basri Gibor Close Laird M McCabe Caer E 2004 08 01 First determination of the dynamical mass of a binary L dwarf Astronomy amp Astrophysics 423 1 341 352 arXiv astro ph 0405111 Bibcode 2004A amp A 423 341B doi 10 1051 0004 6361 20040551 ISSN 0004 6361 S2CID 3149721 Bedin Luigi R Pourbaix Dimitri Apai Daniel Burgasser Adam J Buenzli Esther Boffin Henri M J Libralato Mattia 2017 09 01 Hubble Space Telescope astrometry of the closest brown dwarf binary system I Overview and improved orbit Monthly Notices of the Royal Astronomical Society 470 1 1140 1155 arXiv 1706 00657 doi 10 1093 mnras stx1177 hdl 10150 625503 ISSN 0035 8711 S2CID 119385778 Luhman Kevin L 2004 10 10 The First Discovery of a Wide Binary Brown Dwarf The Astrophysical Journal 614 1 398 403 arXiv astro ph 0407344 Bibcode 2004ApJ 614 398L doi 10 1086 423666 ISSN 0004 637X S2CID 11733526 Reipurth Bo Clarke Cathie June 2003 Brown Dwarfs as Ejected Stellar Embryos Observational Perspectives IAUS 211 13 22 arXiv astro ph 0209005 Bibcode 2003IAUS 211 13R doi 10 1017 s0074180900210188 ISSN 1743 9221 S2CID 16822178 Faherty Jacqueline K Goodman Sam Caselden Dan Colin Guillaume Kuchner Marc J Meisner Aaron M Gagne Jonathan Schneider Adam C Gonzales Eileen C Bardalez Gagliuffi Daniella C Logsdon Sarah E 2020 WISE2150 7520AB A very low mass wide co moving brown dwarf system discovered through the citizen science project Backyard Worlds Planet 9 The Astrophysical Journal 889 2 176 arXiv 1911 04600 Bibcode 2020ApJ 889 176F doi 10 3847 1538 4357 ab5303 S2CID 207863267 Stassun Keivan G Mathieu Robert D Valenti Jeff A March 2006 Discovery of two young brown dwarfs in an eclipsing binary system Nature 440 7082 311 314 Bibcode 2006Natur 440 311S doi 10 1038 nature04570 ISSN 0028 0836 PMID 16541067 S2CID 4310407 a b Stassun Keivan G Mathieu Robert D Valenti Jeff A 2007 A Surprising Reversal of Temperatures in the Brown Dwarf Eclipsing Binary 2MASS J05352184 0546085 The Astrophysical Journal 664 2 1154 1166 arXiv 0704 3106 Bibcode 2007ApJ 664 1154S doi 10 1086 519231 S2CID 15144741 Farihi Jay Christopher Micol October 2004 A Possible Brown Dwarf Companion to the White Dwarf GD 1400 The Astronomical Journal 128 4 1868 arXiv astro ph 0407036 Bibcode 2004AJ 128 1868F doi 10 1086 423919 ISSN 1538 3881 S2CID 119530628 Maxted Pierre Napiwotzki Ralf Dobbie Paul Burleigh Matt A Sub Stellar Jonah Brown Dwarf Survives Being Swallowed Press release European Southern Observatory Retrieved 2019 12 11 Casewell Sarah L Braker Ian P Parsons Steven G Hermes James J Burleigh Matthew R Belardi Claudia Chaushev Alexander Finch Nicolle L Roy Mervyn Littlefair Stuart P Goad Mike Dennihy Erik 31 January 2018 The first sub 70 min non interacting WD BD system EPIC212235321 Monthly Notices of the Royal Astronomical Society 476 1 1405 1411 arXiv 1801 07773 Bibcode 2018MNRAS 476 1405C doi 10 1093 mnras sty245 ISSN 0035 8711 S2CID 55776991 Longstaff Emma S Casewell Sarah L Wynn Graham A Maxted Pierre F L Helling Christiane 2017 10 21 Emission lines in the atmosphere of the irradiated brown dwarf WD0137 349B Monthly Notices of the Royal Astronomical Society 471 2 1728 1736 arXiv 1707 05793 Bibcode 2017MNRAS 471 1728L doi 10 1093 mnras stx1786 ISSN 0035 8711 S2CID 29792989 Grether Daniel Lineweaver Charles H April 2006 How Dry is the Brown Dwarf Desert Quantifying the Relative Number of Planets Brown Dwarfs and Stellar Companions around Nearby Sun like Stars The Astrophysical Journal 640 2 1051 1062 arXiv astro ph 0412356 Bibcode 2006ApJ 640 1051G doi 10 1086 500161 ISSN 0004 637X Rappaport Saul A Vanderburg Andrew Nelson Lorne Gary Bruce L Kaye Thomas G Kalomeni Belinda Howell Steve B Thorstensen John R Lachapelle Francois Rene Lundy Matthew St Antoine Jonathan 2017 10 11 WD 1202 024 the shortest period pre cataclysmic variable Monthly Notices of the Royal Astronomical Society 471 1 948 961 arXiv 1705 05863 Bibcode 2017MNRAS 471 948R doi 10 1093 mnras stx1611 ISSN 0035 8711 S2CID 119349942 Lira Nicolas Blue Charles E Turner Calum Hiramatsu Masaaki When Is a Nova Not a Nova When a White Dwarf and a Brown Dwarf Collide ALMA Observatory Archived from the original on 2019 10 22 Retrieved 2019 11 12 Eyres Stewart P S Evans Aneurin Zijlstra Albert Avison Adam Gehrz Robert D Hajduk Marcin Starrfield Sumner Mohamed Shazrene Woodward Charles E Wagner R Mark 2018 12 21 ALMA reveals the aftermath of a white dwarf brown dwarf merger in CK Vulpeculae Monthly Notices of the Royal Astronomical Society 481 4 4931 4939 arXiv 1809 05849 Bibcode 2018MNRAS 481 4931E doi 10 1093 mnras sty2554 ISSN 0035 8711 S2CID 119462149 Meisner Aaron Kocz Amanda Mapping Our Sun s Backyard NOIRLab Retrieved 1 February 2021 O Neill Ian 12 June 2012 Brown Dwarfs Runts of Stellar Litter Rarer than Thought Space com Retrieved 2012 12 28 Muzic Koraljka Schoedel Rainer Scholz Alexander Geers Vincent C Jayawardhana Ray Ascenso Joana Cieza Lucas A 2017 07 02 The low mass content of the massive young star cluster RCW 38 Monthly Notices of the Royal Astronomical Society 471 3 3699 3712 arXiv 1707 00277 Bibcode 2017MNRAS 471 3699M doi 10 1093 mnras stx1906 ISSN 0035 8711 S2CID 54736762 Apai Daniel Karalidi T Marley Mark S Yang H Flateau D Metchev S Cowan N B Buenzli E Burgasser Adam J Radigan J Artigau Etienne Lowrance P 2017 Zones spots and planetary scale waves beating in brown dwarf atmospheres Science 357 6352 683 687 Bibcode 2017Sci 357 683A doi 10 1126 science aam9848 PMID 28818943 Gohd Chelsea 19 August 2020 Volunteers spot almost 100 cold brown dwarfs near our sun Space com a b Apai Daniel Pascucci Ilaria Bouwman Jeroen Natta Antonella Henning Thomas Dullemond Cornelis P 2005 The Onset of Planet Formation in Brown Dwarf Disks Science 310 5749 834 6 arXiv astro ph 0511420 Bibcode 2005Sci 310 834A doi 10 1126 science 1118042 PMID 16239438 S2CID 5181947 Riaz Basmah Machida Masahiro N Stamatellos Dimitris July 2019 ALMA reveals a pseudo disc in a proto brown dwarf Monthly Notices of the Royal Astronomical Society 486 3 4114 4129 arXiv 1904 06418 Bibcode 2019MNRAS 486 4114R doi 10 1093 mnras stz1032 ISSN 0035 8711 S2CID 119286540 Riaz Basmah Najita Joan Punching Above Its Weight a Brown Dwarf Launches a Parsec Scale Jet National Optical Astronomy Observatory Archived from the original on 2020 02 18 Retrieved 2020 02 18 a b Riaz Basmah Briceno Cesar Whelan Emma T Heathcote Stephen July 2017 First Large scale Herbig Haro Jet Driven by a Proto brown Dwarf Astrophysical Journal 844 1 47 arXiv 1705 01170 Bibcode 2017ApJ 844 47R doi 10 3847 1538 4357 aa70e8 ISSN 0004 637X S2CID 119080074 a b Burrows Adam Hubbard William B Lunine Jonathan I Liebert James 2011 Tidal evolution of planets around brown dwarfs Astronomy amp Astrophysics 535 A94 arXiv 1109 2906 Bibcode 2011A amp A 535A 94B doi 10 1051 0004 6361 201117734 S2CID 118532416 Jewitt David C Pan STARRS Science Overview Archived 2015 10 16 at the Wayback Machine Luhman Kevin L Adame Lucia d Alessio Paola Calvet Nuria Hartmann Lee Megeath S T Fazio G G 2005 Discovery of a Planetary Mass Brown Dwarf with a Circumstellar Disk The Astrophysical Journal 635 1 L93 L96 arXiv astro ph 0511807 Bibcode 2005ApJ 635L 93L doi 10 1086 498868 S2CID 11685964 Ricci Luca Testi Leonardo Pierce Price Douglas Stoke John Even Brown Dwarfs May Grow Rocky Planets Press release European Southern Observatory Archived from the original on 3 December 2012 Retrieved 3 December 2012 Joergens Viki Muller Andre 2007 16 20 MJup Radial Velocity Companion Orbiting the Brown Dwarf Candidate Cha Ha 8 The Astrophysical Journal 666 2 L113 L116 arXiv 0707 3744 Bibcode 2007ApJ 666L 113J doi 10 1086 521825 S2CID 119140521 Joergens Viki Muller Andre Reffert Sabine 2010 Improved radial velocity orbit of the young binary brown dwarf candidate Cha Ha 8 Astronomy and Astrophysics 521 A24 A24 arXiv 1006 2383 Bibcode 2010A amp A 521A 24J doi 10 1051 0004 6361 201014853 S2CID 54989533 Bennet David P Bond Ian A Udalski Andrzej Sumi Takahiro Abe Fumio Fukui Akihiko Furusawa Kei Hearnshaw John B Holderness Sarah Itow Yoshitaka Kamiya Koki Korpela Aarno V Kilmartin Pamela M Lin Wei Ling Cho Hong Masuda Kimiaki Matsubara Yutaka Miyake Noriyuki Muraki Yasushi Nagaya Maiko Okumura Teppei Ohnishi Kouji Perrott Yvette C Rattenbury Nicholas J Sako Takashi Saito Toshiharu Sato S Skuljan Ljiljana Sullivan Denis J Sweatman Winston L Tristram Paul J Yock Philip C M Kubiak Marcin Szymanski Michal K Pietrzynski Grzegorz Soszynski Igor Szewczyk O Wyrzykowski Lukasz Ulaczyk Krzysztof Batista Virginie Beaulieu Jean Philippe Brillant Stephane Cassan Arnaud Fouque Pascal Kervella Pierre Kubas Daniel Marquette Jean Baptiste 30 May 2008 A Low Mass Planet with a Possible Sub Stellar Mass Host in Microlensing Event MOA 2007 BLG 192 The Astrophysical Journal 684 1 663 683 arXiv 0806 0025 Bibcode 2008ApJ 684 663B doi 10 1086 589940 S2CID 14467194 Burrows Adam Hubbard William B Lunine Jonathan I Liebert James 2013 The Atomic and Molecular Content of Disks Around Very Low mass Stars and Brown Dwarfs The Astrophysical Journal 779 2 178 arXiv 1311 1228 Bibcode 2013ApJ 779 178P doi 10 1088 0004 637X 779 2 178 S2CID 119001471 He Matthias Y Triaud Amaury H M J Gillon Michael January 2017 First limits on the occurrence rate of short period planets orbiting brown dwarfs Monthly Notices of the Royal Astronomical Society 464 3 2687 2697 arXiv 1609 05053 Bibcode 2017MNRAS 464 2687H doi 10 1093 mnras stw2391 S2CID 53692008 Barnes Rory Heller Rene 2011 Habitable Planets Around White and Brown Dwarfs The Perils of a Cooling Primary Astrobiology 13 3 279 291 arXiv 1211 6467 Bibcode 2013AsBio 13 279B doi 10 1089 ast 2012 0867 PMC 3612282 PMID 23537137 Morrison David 2 August 2011 Scientists today no longer think an object like Nemesis could exist NASA Ask An Astrobiologist Archived from the original on 13 December 2012 Retrieved 2011 10 22 Whelan Emma T Ray Thomas P Bacciotti Francesca Natta Antonella Testi Leonardo Randich Sofia June 2005 A resolved outflow of matter from a brown dwarf Nature 435 7042 652 654 arXiv astro ph 0506485 Bibcode 2005Natur 435 652W doi 10 1038 nature03598 ISSN 0028 0836 PMID 15931217 S2CID 4415442 Basri Gibor Martin Eduardo L 1999 astro ph 9908015 PPl 15 The First Brown Dwarf Spectroscopic Binary The Astronomical Journal 118 5 2460 2465 arXiv astro ph 9908015 Bibcode 1999AJ 118 2460B doi 10 1086 301079 S2CID 17662168 Stassun Keivan G Mathieu Robert D Valenti Jeff A 2006 03 16 Discovery of two young brown dwarfs in an eclipsing binary system Nature 440 7082 311 314 Bibcode 2006Natur 440 311S doi 10 1038 nature04570 PMID 16541067 S2CID 4310407 Scholz Ralf Dieter McCaughrean Mark 2003 01 13 eso0303 Discovery of Nearest Known Brown Dwarf Press release European Southern Observatory Archived from the original on October 13 2008 Retrieved 2013 03 16 Burrows Adam Hubbard William B Lunine Jonathan I Liebert James 2004 A possible third component in the L dwarf binary system DENIS P J020529 0 115925 discovered with the Hubble Space Telescope The Astronomical Journal 129 1 511 517 arXiv astro ph 0410226 Bibcode 2005AJ 129 511B doi 10 1086 426559 S2CID 119336794 Burgasser Adam J Kirkpatrick J Davy Burrows Adam Liebert James Reid I Neill Gizis John E McGovern Mark R Prato Lisa McLean Ian S 2003 The First Substellar Subdwarf Discovery of a Metal Poor L Dwarf with Halo Kinematics The Astrophysical Journal 592 2 1186 1192 arXiv astro ph 0304174 Bibcode 2003ApJ 592 1186B doi 10 1086 375813 S2CID 11895472 Wolszczan Alexander Route Matthew 2014 Timing Analysis of the Periodic Radio and Optical Brightness Variations of the Ultracool Dwarf TVLM 513 46546 The Astrophysical Journal 788 1 23 arXiv 1404 4682 Bibcode 2014ApJ 788 23W doi 10 1088 0004 637X 788 1 23 S2CID 119114679 Maxted Pierre F L Napiwotzki Ralf Dobbie Paul D Burleigh Matthew R 2006 Survival of a brown dwarf after engulfment by a red giant star Nature Submitted manuscript 442 7102 543 5 arXiv astro ph 0608054 Bibcode 2006Natur 442 543M doi 10 1038 nature04987 hdl 2299 1227 PMID 16885979 S2CID 4368344 Archived from the original on 2021 04 27 Levine Joanna L Steinhauer Aaron Elston Richard J Lada Elizabeth A 2006 08 01 Low Mass Stars and Brown Dwarfs in NGC 2024 Constraints on the Substellar Mass Function The Astrophysical Journal 646 2 1215 1229 arXiv astro ph 0604315 Bibcode 2006ApJ 646 1215L doi 10 1086 504964 ISSN 0004 637X S2CID 118955538 Table 3 FLMN J0541328 0151271 a b Zhang ZengHua Homeier Derek Pinfield David J Lodieu Nicolas Jones Hugh R A Pavlenko Yakiv V 2017 06 11 Primeval very low mass stars and brown dwarfs II The most metal poor substellar object Monthly Notices of the Royal Astronomical Society 468 1 261 arXiv 1702 02001 Bibcode 2017MNRAS 468 261Z doi 10 1093 mnras stx350 S2CID 54847595 Tannock Megan E Metchev Stanimir Heinze Aren Miles Paez Paulo A Gagne Jonathan Burgasser Adam J Marley Mark S Apai Daniel Suarez Genaro Plavchan Peter March 2021 Weather on Other Worlds V The Three Most Rapidly Rotating Ultra cool Dwarfs The Astronomical Journal 161 5 224 arXiv 2103 01990 Bibcode 2021AJ 161 224T doi 10 3847 1538 3881 abeb67 S2CID 232105126 The Extrasolar Planet Encyclopaedia KMT 2016 BLG 2142 b exoplanet eu Retrieved 2021 01 12 Route Matthew Wolszczan Alexander 2012 The Arecibo Detection of the Coolest Radio flaring Brown Dwarf The Astrophysical Journal 2012 747 L22 arXiv 1202 1287 Bibcode 2012ApJ 747L 22R doi 10 1088 2041 8205 747 2 L22 S2CID 119290950 Astrobites 24 June 2020 Transiting Brown Dwarfs from TESS 2 AAS Nova Retrieved 2013 03 16 Tannock Megan Metchev Stanimir Kocz Amanda 7 April 2021 Caught Speeding Clocking the Fastest Spinning Brown Dwarfs NOIRLab Retrieved 9 April 2021 External links Edit Look up brown dwarf in Wiktionary the free dictionary Wikimedia Commons has media related to Brown dwarf HubbleSite newscenter Weather patterns on a brown dwarf Allard France Homeier Derek 2007 Brown dwarfs Scholarpedia 2 12 4475 Bibcode 2007SchpJ 2 4475A doi 10 4249 scholarpedia 4475 History Edit Kumar Shiv S Low Luminosity Stars Gordon and Breach London 1969 an early overview paper on brown dwarfs The Columbia Encyclopedia Brown Dwarfs Details Edit A current list of L and T dwarfs A geological definition of brown dwarfs contrasted with stars and planets via Berkeley I Neill Reid s pages at the Space Telescope Science Institute On spectral analysis of M dwarfs L dwarfs and T dwarfs Temperature and mass characteristics of low temperature dwarfs First X ray from brown dwarf observed Spaceref com 2000 Montes David Brown Dwarfs and ultracool dwarfs late M L T UCM Wild Weather Iron Rain on Failed Stars scientists are investigating astonishing weather patterns on brown dwarfs Space com 2006 NASA Brown dwarf detectives Detailed information in a simplified sense Brown Dwarfs Website with general information about brown dwarfs has many detailed and colorful artist s impressions Stars Edit Cha Halpha 1 stats and history A census of observed brown dwarfs not all confirmed 1998 Luhman Kevin L Adame Lucia d Alessio Paola Calvet Nuria Hartmann Lee Megeath S Thomas Fazio Giovanni G 2005 Discovery of a Planetary Mass Brown Dwarf with a Circumstellar Disk The Astrophysical Journal 635 1 L93 L96 arXiv astro ph 0511807 Bibcode 2005ApJ 635L 93L doi 10 1086 498868 S2CID 11685964 Michaud Peter Heyer Inge Leggett Sandy K and Adamson Andy Discovery Narrows the Gap Between Planets and Brown Dwarfs Gemini and Joint Astronomy Centre 2007 Deacon Niall R and Hambly Nigel C Y Spectral class for Ultra Cool Dwarfs 2006 Portals Astronomy Stars Outer space Retrieved from https en wikipedia org w index php title Brown dwarf amp oldid 1134415657, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.