NGC 281, IC 11 or Sh2-184 is a bright emission nebula and part of an H II region in the northern constellation of Cassiopeia and is part of the Milky Way's Perseus Spiral Arm. This 20×30 arcmin sized nebulosity is also associated with open clusterIC 1590, several Bok globules and the multiple star, B 1. It collectively forms Sh2-184,[3] spanning over a larger area of 40 arcmin.[4] A recent distance from radio parallaxes of water masers at 22 GHz made during 2014 is estimated it lies 2.82±0.20 kpc. (9200 ly.) from us.[5] Colloquially, NGC 281 is also known as the Pacman Nebula for its resemblance to the video game character.
Edward Emerson Barnard discovered the nebula in August 1883, describing it as "a large faint nebula, very diffuse". Multiple star 'B 1' or β 1 was later discovered by S. W. Burnham, whose bright component is identified as the highly luminous O6 spectral class star, HD 5005 or HIP 4121. It consists of an 8th-magnitude primary with four companions at distances between 1.4 and 15.7 arcsec. There has been no appreciable change in this quintuple system since the first measures were made in 1875.
The nebula region is visible in amateur telescopes from dark sky locations. In his book Deep Sky Wonders, Walter Scott Houston describes the appearance of the nebula in small telescopes:[6]
"There was a faint glow in the immediate vicinity of the multiple star, with an occasional impression of a much larger nebulosity...Its surface brightness was much less than that of M33 in Triangulum or NGC 205, the distant companion of the Andromeda galaxy."
Galleryedit
NGC 281 in the optical (red, yellow) and X rays (blue)
Young open star cluster IC 1590, which is found within the star formation region NGC 281
Referencesedit
^ abc"NASA/IPAC Extragalactic Database". Results for NGC 281. Retrieved 2006-10-17.
^Leass, E. A.; Biller, B.; Dame, T. M.; Megeath, S. T. (2001). "An Expanding Complex of Molecular Clouds High Above the Perseus Spiral Arm". American Astronomical Society, 199th AAS Meeting, #91.16; Bulletin of the American Astronomical Society. 33: 1439. Bibcode:2001AAS...199.9116L.
^Choi, Y.K.; et al. (2014). "Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm". Astrophysical Journal. 790 (2): 99. arXiv:1407.1609. Bibcode:1959ApJ...790...99C. doi:10.1088/0004-637X/790/2/99. S2CID 118399182. Retrieved 18 March 2017.
NGC 281 Astronomy picture of the Day (August 23, 2005) at NASA
NASA Astronomy Picture of the Day: Portrait of NGC 281 (25 August 2011)
NGC 281 at Deep Space Map
April 10, 2024
bright, emission, nebula, part, region, northern, constellation, cassiopeia, part, milky, perseus, spiral, this, arcmin, sized, nebulosity, also, associated, with, open, cluster, 1590, several, globules, multiple, star, collectively, forms, spanning, over, lar. NGC 281 IC 11 or Sh2 184 is a bright emission nebula and part of an H II region in the northern constellation of Cassiopeia and is part of the Milky Way s Perseus Spiral Arm This 20 30 arcmin sized nebulosity is also associated with open cluster IC 1590 several Bok globules and the multiple star B 1 It collectively forms Sh2 184 3 spanning over a larger area of 40 arcmin 4 A recent distance from radio parallaxes of water masers at 22 GHz made during 2014 is estimated it lies 2 82 0 20 kpc 9200 ly from us 5 Colloquially NGC 281 is also known as the Pacman Nebula for its resemblance to the video game character NGC 281Emission nebulaH II regionNGC 281 in the classic Hubble Palette Ha OIII SII by amateur astronomer Chuck AyoubObservation data J2000 0 epochRight ascension00h 52m 59 3s 1 Declination 56 37 19 1 Distance9500 2 ly 2900 pc Apparent dimensions V 35 ConstellationCassiopeiaPhysical characteristicsRadius48 lyNotable featuresopen cluster IC 1590 the multiple star B 1 and several Bok globulesDesignationsIC 11 Sh2 184 3 Sharpless 184 1 LBN 616 LBN 123 17 06 28 Pacman NebulaSee also Lists of nebulaeEdward Emerson Barnard discovered the nebula in August 1883 describing it as a large faint nebula very diffuse Multiple star B 1 or b 1 was later discovered by S W Burnham whose bright component is identified as the highly luminous O6 spectral class star HD 5005 or HIP 4121 It consists of an 8th magnitude primary with four companions at distances between 1 4 and 15 7 arcsec There has been no appreciable change in this quintuple system since the first measures were made in 1875 The nebula region is visible in amateur telescopes from dark sky locations In his book Deep Sky Wonders Walter Scott Houston describes the appearance of the nebula in small telescopes 6 There was a faint glow in the immediate vicinity of the multiple star with an occasional impression of a much larger nebulosity Its surface brightness was much less than that of M33 in Triangulum or NGC 205 the distant companion of the Andromeda galaxy Gallery edit nbsp NGC 281 in the optical red yellow and X rays blue nbsp Young open star cluster IC 1590 which is found within the star formation region NGC 281References edit a b c NASA IPAC Extragalactic Database Results for NGC 281 Retrieved 2006 10 17 Leass E A Biller B Dame T M Megeath S T 2001 An Expanding Complex of Molecular Clouds High Above the Perseus Spiral Arm American Astronomical Society 199th AAS Meeting 91 16 Bulletin of the American Astronomical Society 33 1439 Bibcode 2001AAS 199 9116L a b NGC 281 SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 18 March 2017 Sharpless S 1959 A Catalogue of H II Regions Astrophysical Journal Supplement 4 257 Bibcode 1959ApJS 4 257S doi 10 1086 190049 Retrieved 18 March 2017 Choi Y K et al 2014 Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm Astrophysical Journal 790 2 99 arXiv 1407 1609 Bibcode 1959ApJ 790 99C doi 10 1088 0004 637X 790 2 99 S2CID 118399182 Retrieved 18 March 2017 Houston Walter Scott 2005 Deep Sky Wonders Sky Publishing Corporation ISBN 978 1 931559 23 2 External links edit nbsp Wikimedia Commons has media related to NGC 281 NGC 281 Astronomy picture of the Day August 23 2005 at NASA NASA Astronomy Picture of the Day Portrait of NGC 281 25 August 2011 NGC 281 at ESA Hubble NGC 281 at Deep Space Map Retrieved from https en wikipedia org w index php title NGC 281 amp oldid 1210316408, wikipedia, wiki, book, books, library,
