It has been suggested that Kepler-1708b I be merged into this article. (Discuss) Proposed since January 2024.
Kepler-1708b (previously known as KIC 7906827.01) is a Jupiter-sized exoplanet orbiting the Sun-like star Kepler-1708, located in the constellation of Cygnus approximately 5,600 light years away from Earth.[1] It was first detected in 2011 by NASA's Kepler mission using the transit method, but was not identified as a candidate planet until 2019.[2][3] In 2021, a candidate Neptune-sized exomoon in orbit around Kepler-1708b was found by astronomer David Kipping and colleagues in an analysis using Kepler transit data.[1][4] However, subsequent research has raised discrepancies about the possible existence of an exomoon, similar to that of Kepler-1625b.[5]
Kepler-1708b is a gas giant planet slightly smaller than Jupiter in size, with a radius of 0.89 Jupiter radii.[6][4] The mass of the planet remains yet to be measured; precise analysis of its transit timings place a 2-sigma upper limit of <4.6 Jupiter masses. This mass upper limit predicts a maximum radial velocity amplitude of <98 m/s—although within reach of the most precise spectrographs available, the faintness of Kepler-1708b's host star would make observations difficult.[1][7]
Orbit and temperatureedit
Kepler-1708b orbits about 1.64 astronomical units from its host star and completes one revolution every 737.11 days or 2.02 years, comparable to the orbit of Mars in the Solar System.[8] At this distance, Kepler-1708b lies within the habitable zone of its host star, where it receives an insolation flux0.561+0.074 −0.068 times that of Earth at a relatively cool equilibrium temperature of 200–300 kelvins (−73–27 °C; −100–80 °F).[1][9] The eccentricity of its orbit is unmeasured and is given a 2-sigma upper limit of <0.40.[1]
Kepler-1708 is slightly larger and more massive than the Sun, with a mass of 1.088±0.072 M☉ and radius of 1.117±0.064 R☉. It is also hotter and more luminous than the Sun, with an effective temperature of 6,157+231 −202K and a bolometric luminosity of 1.521 L☉.[a] Based on these properties, Kepler-1708 is likely an F-type main sequence star with a Sun-like metallicity of [Fe/H] = 0.0±0.2 dex and an age of 3.16±2.26 billion years.[b][6][1]
Kepler-1708b and its possible exomoon, rendered in Celestia.
In 2021, David Kipping and colleagues performed a search for exomoons around cool, long-period gas giant exoplanets using Kepler photometric data. Out of a sample of 70 exoplanets analyzed, only Kepler-1708b exhibited signs of an orbiting exomoon manifesting as faint, secondary transits accompanying the planet's transits.[11] This possible exomoon, designated Kepler-1708b I, appears to measure below the size of Neptune at 2.6 times Earth's radius. It likely orbits coplanar to its host planet from a distance up to 12 planetary radii—comparable to the distance between Jupiter and its moon Europa, or twice the Earth–Moon distance.[1][12] The extraordinarily large size of Kepler-1708b I is reminiscent of Kepler-1625b I, another Neptune-sized exomoon candidate previously reported by Kipping et al. in 2017.[1]
Additional observations are necessary to confirm or refute the exomoon's existence—only two transits by Kepler-1708b and its possible exomoon have been observed, and no transit timing variations can be determined as of yet. Kipping et al. determine that the probability of detecting one false positive exomoon in the studied sample of 70 exoplanets was <50%. A follow-up study suggested Kepler-1708b I is likely undetectable with the Hubble Space Telescope, but the James Webb Space Telescope should be able to confirm or refute its existence.[13]
In 2024, a paper was published disputing both 1625b I and 1708b I’s existences.[5]
^Luminosity calculated from the inverse of from Kipping et al. (2022)[1]
^Age calculated from the inverse of from Kipping et al. (2022)[1]
Referencesedit
^ abcdefghijklmnoKipping, David; Bryson, Steve; Burke, Chris; Christiansen, Jessie; Hardegree-Ullman, Kevin; Quarles, Billy; Hansen, Brad; Szulágyi, Judit; Teachey, Alex (January 2022). "An exomoon survey of 70 cool giant exoplanets and the new candidate Kepler-1708 b-i" (PDF). Nature Astronomy. 6 (3): 367–380. arXiv:2201.04643. Bibcode:2022NatAs...6..367K. doi:10.1038/s41550-021-01539-1. PMC8938273. PMID 35399159. S2CID 245906142.
^ abHerman, Miranda K.; Zhu, Wei; Wu, Yanqin (June 2019). "Revisiting the Long-period Transiting Planets from Kepler". The Astronomical Journal. 157 (6): 15. arXiv:1901.01974. Bibcode:2019AJ....157..248H. doi:10.3847/1538-3881/ab1f70. S2CID 119550672. 248.
^ abKawahara, Hajime; Masuda, Kento (June 2019). "Transiting Planets Near the Snow Line from Kepler. I. Catalog". The Astronomical Journal. 157 (6): 27. arXiv:1904.04980. Bibcode:2019AJ....157..218K. doi:10.3847/1538-3881/ab18ab. S2CID 119099510. 218.
^ abcd"Kepler-1708 Overview". NASA Exoplanet Archive. Infrared Processing and Analysis Center. Retrieved 16 January 2022.
^"Scientists think they've found a big, weird moon in a far-off star system". NPR.org. Retrieved 2022-03-28.
^O'Callaghan, Jonathan (13 January 2022). "Astronomers Have Found Another Possible 'Exomoon' beyond Our Solar System". Scientific American. Retrieved 16 January 2022.
^Cassese, Ben; Kipping, David (2022-03-24). "Kepler-1708 b-i is likely undetectable with HST". Monthly Notices of the Royal Astronomical Society. 516 (3): 3701–3708. arXiv:2203.13290. doi:10.1093/mnras/stac2090.
External linksedit
Astronomers Find Evidence for a Second Supermoon Beyond Our Solar System, Kim Martineau, Columbia News, Columbia University, 13 January 2022
kepler, 1708b, been, suggested, that, merged, into, this, article, discuss, proposed, since, january, 2024, previously, known, 7906827, jupiter, sized, exoplanet, orbiting, like, star, kepler, 1708, located, constellation, cygnus, approximately, light, years, . It has been suggested that Kepler 1708b I be merged into this article Discuss Proposed since January 2024 Kepler 1708b previously known as KIC 7906827 01 is a Jupiter sized exoplanet orbiting the Sun like star Kepler 1708 located in the constellation of Cygnus approximately 5 600 light years away from Earth 1 It was first detected in 2011 by NASA s Kepler mission using the transit method but was not identified as a candidate planet until 2019 2 3 In 2021 a candidate Neptune sized exomoon in orbit around Kepler 1708b was found by astronomer David Kipping and colleagues in an analysis using Kepler transit data 1 4 However subsequent research has raised discrepancies about the possible existence of an exomoon similar to that of Kepler 1625b 5 Kepler 1708bDiscovery 1 Discovery date2019 candidate 2 3 2021 confirmed 1 4 Detection methodTransitDesignationsAlternative namesKIC 7906827 01Orbital characteristics 1 Semi major axis1 64 0 10 AUEccentricity lt 0 40Orbital period sidereal 737 1131 0 00146 0 00770 dInclination89 92 0 03 0 01 StarKepler 1708Physical characteristics 1 Mean radius0 8886 0 0535 0 0526 RJ 4 Mass lt 4 6 MJ Contents 1 Characteristics 1 1 Mass and radius 1 2 Orbit and temperature 2 Host star 3 Potential exomoon 4 See also 5 Notes 6 References 7 External linksCharacteristics editMass and radius edit Kepler 1708b is a gas giant planet slightly smaller than Jupiter in size with a radius of 0 89 Jupiter radii 6 4 The mass of the planet remains yet to be measured precise analysis of its transit timings place a 2 sigma upper limit of lt 4 6 Jupiter masses This mass upper limit predicts a maximum radial velocity amplitude of lt 98 m s although within reach of the most precise spectrographs available the faintness of Kepler 1708b s host star would make observations difficult 1 7 Orbit and temperature edit Kepler 1708b orbits about 1 64 astronomical units from its host star and completes one revolution every 737 11 days or 2 02 years comparable to the orbit of Mars in the Solar System 8 At this distance Kepler 1708b lies within the habitable zone of its host star where it receives an insolation flux 0 561 0 074 0 068 times that of Earth at a relatively cool equilibrium temperature of 200 300 kelvins 73 27 C 100 80 F 1 9 The eccentricity of its orbit is unmeasured and is given a 2 sigma upper limit of lt 0 40 1 Host star editKepler 1708b orbits around the Sun like star Kepler 1708 located in the constellation of Cygnus 5 580 240 ly 1 712 75 pc light years away from Earth 1 At an apparent magnitude of 16 this star is too faint to be seen by the naked eye 10 The star s celestial coordinates based on the J2000 epoch are RA 19h 47m 17 79s Dec 43 37 29 4 10 The European Space Agency s Gaia satellite has measured a stellar parallax of 0 5730 0 0340 milliarcseconds mas and directional proper motion components of RA 0 770 0 057 mas yr Dec 5 005 0 059 mas yr 10 Kepler 1708 is known by other designations from various star catalogues including UCAC4 669 077544 KIC 7906827 TIC 272716898 2MASS J19471778 4337295 WISE J194717 78 433729 2 and Gaia DR2 2078801971283008128 10 Kepler 1708 is slightly larger and more massive than the Sun with a mass of 1 088 0 072 M and radius of 1 117 0 064 R It is also hotter and more luminous than the Sun with an effective temperature of 6 157 231 202 K and a bolometric luminosity of 1 521 L a Based on these properties Kepler 1708 is likely an F type main sequence star with a Sun like metallicity of Fe H 0 0 0 2 dex and an age of 3 16 2 26 billion years b 6 1 Potential exomoon editMain article Kepler 1708b I nbsp Kepler 1708b and its possible exomoon rendered in Celestia In 2021 David Kipping and colleagues performed a search for exomoons around cool long period gas giant exoplanets using Kepler photometric data Out of a sample of 70 exoplanets analyzed only Kepler 1708b exhibited signs of an orbiting exomoon manifesting as faint secondary transits accompanying the planet s transits 11 This possible exomoon designated Kepler 1708b I appears to measure below the size of Neptune at 2 6 times Earth s radius It likely orbits coplanar to its host planet from a distance up to 12 planetary radii comparable to the distance between Jupiter and its moon Europa or twice the Earth Moon distance 1 12 The extraordinarily large size of Kepler 1708b I is reminiscent of Kepler 1625b I another Neptune sized exomoon candidate previously reported by Kipping et al in 2017 1 Additional observations are necessary to confirm or refute the exomoon s existence only two transits by Kepler 1708b and its possible exomoon have been observed and no transit timing variations can be determined as of yet Kipping et al determine that the probability of detecting one false positive exomoon in the studied sample of 70 exoplanets was lt 50 A follow up study suggested Kepler 1708b I is likely undetectable with the Hubble Space Telescope but the James Webb Space Telescope should be able to confirm or refute its existence 13 In 2024 a paper was published disputing both 1625b I and 1708b I s existences 5 See also editKepler 1625b 2MASS J11193254 1137466 AB PDS 70 V1400 CentauriNotes edit Luminosity calculated from the inverse of log 10 L 0 182 0 082 displaystyle log 10 L ast 0 182 pm 0 082 nbsp from Kipping et al 2022 1 Age calculated from the inverse of log 10 A 9 50 0 31 displaystyle log 10 A 9 50 pm 0 31 nbsp from Kipping et al 2022 1 References edit a b c d e f g h i j k l m n o Kipping David Bryson Steve Burke Chris Christiansen Jessie Hardegree Ullman Kevin Quarles Billy Hansen Brad Szulagyi Judit Teachey Alex January 2022 An exomoon survey of 70 cool giant exoplanets and the new candidate Kepler 1708 b i PDF Nature Astronomy 6 3 367 380 arXiv 2201 04643 Bibcode 2022NatAs 6 367K doi 10 1038 s41550 021 01539 1 PMC 8938273 PMID 35399159 S2CID 245906142 a b Herman Miranda K Zhu Wei Wu Yanqin June 2019 Revisiting the Long period Transiting Planets from Kepler The Astronomical Journal 157 6 15 arXiv 1901 01974 Bibcode 2019AJ 157 248H doi 10 3847 1538 3881 ab1f70 S2CID 119550672 248 a b Kawahara Hajime Masuda Kento June 2019 Transiting Planets Near the Snow Line from Kepler I Catalog The Astronomical Journal 157 6 27 arXiv 1904 04980 Bibcode 2019AJ 157 218K doi 10 3847 1538 3881 ab18ab S2CID 119099510 218 a b c d Kepler 1708 Overview NASA Exoplanet Archive Infrared Processing and Analysis Center Retrieved 16 January 2022 a b https ui adsabs harvard edu abs 2024NatAs 8 193H abstract a b Kepler 1708 b NASA Exoplanet Exploration NASA Retrieved 16 January 2022 Timmermann Anina Heller Rene Reiners Ansgar Zechmeister Mathias March 2020 Radial velocity constraints on the long period transiting planet Kepler 1625 b with CARMENES PDF Astronomy amp Astrophysics 635 2 arXiv 2001 10867 Bibcode 2020A amp A 635A 59T doi 10 1051 0004 6361 201937325 S2CID 210942758 A59 Skuse Ben 14 January 2022 Needle in the Haystack New Exomoon Candidate Found Sky amp Telescope Retrieved 16 January 2022 Kane Stephen Gelino Dawn Habitable Zone Gallery Retrieved 16 January 2022 a b c d UCAC4 669 077544 Star SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 16 January 2022 Scientists think they ve found a big weird moon in a far off star system NPR org Retrieved 2022 03 28 O Callaghan Jonathan 13 January 2022 Astronomers Have Found Another Possible Exomoon beyond Our Solar System Scientific American Retrieved 16 January 2022 Cassese Ben Kipping David 2022 03 24 Kepler 1708 b i is likely undetectable with HST Monthly Notices of the Royal Astronomical Society 516 3 3701 3708 arXiv 2203 13290 doi 10 1093 mnras stac2090 External links editAstronomers Find Evidence for a Second Supermoon Beyond Our Solar System Kim Martineau Columbia News Columbia University 13 January 2022 KIC 7906827 Kepler Time Series Visualizer NASA Exoplanet Archive Infrared Processing and Analysis Center Planet Kepler 1708 b The Extrasolar Planets Encyclopaedia last updated 14 January 2022 Retrieved from https en wikipedia org w index php title Kepler 1708b amp oldid 1219986068 Host star, wikipedia, wiki, book, books, library,
