NGC 2261 (also known as Hubble's Variable Nebula or Caldwell 46) is a variable nebula located in the constellationMonoceros. The nebula is illuminated by the star R Monocerotis (R Mon), which is not directly visible itself.
The first recorded observation of the nebula was by William Herschel on 26 December 1783, being described as considerably bright and 'fan-shaped'.[2] It had long been designated as H IV 2, after being the second entry of Herschel's class 4 category for nebulae and star clusters, in his catalogues of nebulae.[3]
NGC 2261 was imaged as Palomar Observatory's Hale Telescope's first light by Edwin Hubble on January 26, 1949,[4] some 20 years after the Palomar Observatory project began in 1928. Hubble had studied the nebula previously at Yerkes and Mt. Wilson.[4] Hale had taken photographic plates with a 24-inch (60.96 cm) reflecting telescope in 1916.[5] Also, plates were taken using the same telescope in 1908 by FC Jordan, allowing Hale to use of a blink comparator to study any changes in the nebula.[5]
NGC 2261 was imaged by the Hubble Space Telescope, and an image of the nebula was released in 1999.[6]
A timelapse of NGC 2261 was provided showing a period of 6 months, from October 2021-April 2022. This was shot by over 20 astronomers at the Big Amateur Telescope. In August of 2022 the project was resumed as NGC 2261 came out from behind the sun.[7]
Timelapse of NGC 2261 over 6 months.
Descriptions
The star R Monocerotis has lit up a nearby cloud of gas and dust, but the shape and brightness slowly changes visibly even in small telescopes over weeks and months, and the nebula looks like a small comet.[8]
One explanation proposed for the variability is that dense clouds of dust near R Mon periodically block the illumination from the star.[9] This casts a temporary shadow on the nearby clouds.[10]
^Herschel, William (1786). "Catalogue of One Thousand New Nebulae and Clusters of Stars. By William Herschel, LL.D. F. R. S." Philosophical Transactions of the Royal Society of London. 76: 457–499. ISSN 0261-0523. JSTOR 106639.
^Duncan, John C. (1956). "Lampland's Study of Hubble's Variable Nebula, NGC 2261". Publications of the Astronomical Society of the Pacific. 68 (405): 517–519. doi:10.1086/126989. ISSN 0004-6280. JSTOR 40676213. S2CID 119513655.
^"Hubble's Variable Nebula, NGC 2261". Planetary Science Institute. 2010-10-15. Retrieved 2018-07-25.
^Arny, T. T.; Bechis, K. P. (1978). "A model for the cometary nebula NGC 2261". The Astrophysical Journal. 226: 455. Bibcode:1978ApJ...226..455A. doi:10.1086/156627.
wikispaces.com Archived 2013-02-09 at archive.today – Images by amateur astronomers
Astrobiscuit: Seeing The Speed Of Light fun and educational video about variable nebula and the amateur community observing them
NASA Astronomy Picture of the Day: NGC 2261: Hubble s Variable Nebula (November 8, 2017)
NGC 2261 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
March 06, 2023
2261, also, known, hubble, variable, nebula, caldwell, variable, nebula, located, constellation, monoceros, nebula, illuminated, star, monocerotis, which, directly, visible, itself, reflection, nebulavariable, nebulaan, image, hubble, space, telescopecredit, n. NGC 2261 also known as Hubble s Variable Nebula or Caldwell 46 is a variable nebula located in the constellation Monoceros The nebula is illuminated by the star R Monocerotis R Mon which is not directly visible itself NGC 2261Reflection nebulaVariable NebulaAn image of NGC 2261 by the Hubble Space TelescopeCredit HST NASA JPL Judy SchmidtObservation data J2000 0 epochRight ascension6h 39m 10s 1 Declination 8 45 1 Distance2 500 lyApparent magnitude V 9 0Apparent dimensions V 2 ConstellationMonocerosDesignationsHubble s Variable Nebula 1 Caldwell 46See also Lists of nebulae Contents 1 Observing history 2 Descriptions 3 See also 4 References 5 External linksObserving history EditThe first recorded observation of the nebula was by William Herschel on 26 December 1783 being described as considerably bright and fan shaped 2 It had long been designated as H IV 2 after being the second entry of Herschel s class 4 category for nebulae and star clusters in his catalogues of nebulae 3 NGC 2261 was imaged as Palomar Observatory s Hale Telescope s first light by Edwin Hubble on January 26 1949 4 some 20 years after the Palomar Observatory project began in 1928 Hubble had studied the nebula previously at Yerkes and Mt Wilson 4 Hale had taken photographic plates with a 24 inch 60 96 cm reflecting telescope in 1916 5 Also plates were taken using the same telescope in 1908 by FC Jordan allowing Hale to use of a blink comparator to study any changes in the nebula 5 NGC 2261 was imaged by the Hubble Space Telescope and an image of the nebula was released in 1999 6 A timelapse of NGC 2261 was provided showing a period of 6 months from October 2021 April 2022 This was shot by over 20 astronomers at the Big Amateur Telescope In August of 2022 the project was resumed as NGC 2261 came out from behind the sun 7 Timelapse of NGC 2261 over 6 months Descriptions EditThe star R Monocerotis has lit up a nearby cloud of gas and dust but the shape and brightness slowly changes visibly even in small telescopes over weeks and months and the nebula looks like a small comet 8 One explanation proposed for the variability is that dense clouds of dust near R Mon periodically block the illumination from the star 9 This casts a temporary shadow on the nearby clouds 10 See also EditNGC 1555 New General CatalogueReferences Edit a b c NGC 2261 SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 2007 04 11 Herschel William 1786 Catalogue of One Thousand New Nebulae and Clusters of Stars By William Herschel LL D F R S Philosophical Transactions of the Royal Society of London 76 457 499 ISSN 0261 0523 JSTOR 106639 Duncan John C 1956 Lampland s Study of Hubble s Variable Nebula NGC 2261 Publications of the Astronomical Society of the Pacific 68 405 517 519 doi 10 1086 126989 ISSN 0004 6280 JSTOR 40676213 S2CID 119513655 a b Citizen Science 26 January 2009 a b Hubble E P 1916 The variable nebula NGC 2261 Astrophysical Journal 44 190 Bibcode 1916ApJ 44 190H doi 10 1086 142284 Hubble s variable nebula NGC 2261 www spacetelescope org Retrieved 2018 07 25 Hubble s variable nebula Project bigamateurtelescope com Retrieved 2022 12 24 Hubble s Variable Nebula NGC 2261 Planetary Science Institute 2010 10 15 Retrieved 2018 07 25 Arny T T Bechis K P 1978 A model for the cometary nebula NGC 2261 The Astrophysical Journal 226 455 Bibcode 1978ApJ 226 455A doi 10 1086 156627 NGC 2261 Hubble s Variable Nebula Science Mission Directorate science nasa gov Retrieved 2018 07 25 External links Edit Wikimedia Commons has media related to NGC 2261 European Homepage for the HST Hubble photos and information on NGC 2261 wikispaces com Archived 2013 02 09 at archive today Images by amateur astronomers Astrobiscuit Seeing The Speed Of Light fun and educational video about variable nebula and the amateur community observing them NASA Astronomy Picture of the Day NGC 2261 Hubble s Variable Nebula November 8 2017 NGC 2261 on WikiSky DSS2 SDSS GALEX IRAS Hydrogen a X Ray Astrophoto Sky Map Articles and images Retrieved from https en wikipedia org w index php title NGC 2261 amp oldid 1141774495, wikipedia, wiki, book, books, library,
