List of largest known stars

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Below is a list of the largest known stars by radius. The unit of measurement used is the radius of the Sun (approximately 695,500 kilometers, or 432,450 miles).

The exact order of this list is not complete, nor is it perfectly defined:

  • There are sometimes high uncertainties in derived values and sizes;
  • The distances to most of these stars are uncertain to differing degrees and this uncertainty affects the size measurements;
  • All the stars in this list have extended atmospheres, many are embedded in mostly opaque dust shells or disks, and most pulsate, such that their radii are not well defined;
  • There are theoretical reasons for expecting that no stars in our galaxy are larger than approximately 1,500 times the sun, based on evolutionary models and the Hayashi instability zone. The exact limit depends on the metallicity of the star, so for example supergiants in the Magellanic Clouds have slightly different limiting temperature and luminosity. Stars exceeding the limit have been seen to undergo large eruptions and to change their spectral type over just a few months;
  • A survey of the Magellanic Clouds has catalogued most of the red supergiants and 44 of them are larger than the 700 solar radii cutoff point of this table, with the largest at 1,200-1,300.[1]

List[edit]

List of the largest stars
Star name Solar radii
(Sun = 1)
Notes
UY Scuti 1,708[2] Error in size determination: ±192 solar radii. At the smallest, it would have a size similar to VX Sagittarii (see below).
NML Cygni 1,650[3]
WOH G64 1,540[4] This would be the largest star in the LMC, but is unusual in position and motion and might still be a foreground halo giant.
Westerlund 1-26 1,530-1,580[5](–2,544) [6][7] Very uncertain parameters for an unusual star with strong radio emission. The spectrum is variable but apparently the luminosity is not.
VX Sagittarii 1,520[8] VX Sgr is a pulsating variable with a large visual range and varies significantly in size.
KY Cygni 1,420–2,850 [9] The upper estimate is due to an unusual K band measurement and thought to be an artifact of a reddening correction error. The lower estimate is consistent with other stars in the same survey and with theoretical models.
VY Canis Majoris 1,420 Once thought to be a star so large that it contradicted stellar evolutionary theory, improved measurements have brought it down to size.[10][11]
AH Scorpii 1,287-1,535[2] AH Sco is variable by nearly 3 magnitudes in the visual range, and an estimated 20% in total luminosity. The variation in diameter is not clear because the temperature also varies.
RW Cephei 1,260–1,610 [citation needed] RW Cep is variable both in brightness (by at least a factor of 3) and spectral type (observed from G8 to M), thus probably also in diameter. Because the spectral type and temperature at maximum luminosity are not known, the quoted sizes are just estimates.
PZ Cassiopeiae 1,190-1,940[9]1,260-1,340[12] The largest estimate is due to an unusual K band measurement and thought to be an artifact of a reddening correction error. The lowest estimate is consistent with other stars in the same survey and with theoretical models, and the intermediate ones have been obtained refining the distance to this star, and thus its parameters.
VV Cephei A 1,050–1,900 VV Cep A is a highly distorted star in a close binary system, losing mass to the secondary for at least part of its orbit.
HR 5171 A 1,056–1,575[13] HR 5171 A is a highly distorted star in a close binary system, losing mass to the secondary.
KW Sagittarii 1,009[2]-1,460[9]
Mu Cephei (Herschel's "Garnet Star") 650[14]-1,420[9]
BI Cygni 916[8]-1,240[9]
V354 Cephei 690[8]-1,520[9]
S Persei 780-1,230[9] In the Perseus Double Cluster
BC Cygni 1,140[9]
RT Carinae 1,090[9]
V396 Centauri 1,070[9]
CK Carinae 1,060[9]
V1749 Cygni 620-1,040[9]
RS Persei 1,000[9] In the Perseus Double Cluster
NR Vulpeculae 980[9]
RW Cygni 980[9]
Betelgeuse (Alpha Orionis) 950[15]
Antares A (Alpha Scorpii A) 883
V602 Carinae 860[9]
TZ Cassiopeiae 800[9]
IX Carinae 790[9]
SU Persei 780[9] In the Perseus Double Cluster
TV Geminorum 770[9]
V355 Cepheus 300[8]-770[9]
V382 Carinae 700 Yellow hypergiant, one of the rarest types of star.
The following well-known stars are listed for the purpose of comparison.
CE Tauri ("Ruby Star")[16] 608 Can be occulted by the Moon, allowing accurate determination of its apparent diameter.
Alpha Herculis (Ras Algethi) 460
Rho Cassiopeiae 450 Yellow hypergiant
Mira A (Omicron Ceti) 400[17] Prototype Mira variable
V838 Monocerotis 380 Once topped to the list as one of the largest known stars, after experiencing a nova outburst it gradually decreased in size
The Pistol Star 306 Blue hypergiant, among the most massive and luminous stars known.
La Superba (Y Canum Venaticorum) 215 One of the coolest and reddest known stars.
Eta Carinae (Tseen She) 85–195[18] Previously thought to be the most massive single star, but in 2005 it was realised to be a binary system
Peony Nebula Star 100 Candidate for most luminous star in the Milky Way.
Rigel (Beta Orionis) 78
Canopus (Alpha Carinae) 65 Second brightest star in the night sky.
Aldebaran (Alpha Tauri) 44.2[19]
R136a1 35.4 Also on record as the most massive and luminous star known.
HDE226868 20-22 The supergiant companion of black hole Cygnus X-1. The black hole is 500,000 times smaller than the star.
VV Cephei B 10

See also[edit]

References[edit]

  1. ^ Levesque, E. M.; Massey, P.; Olsen, K. A. G.; Plez, B.; Meynet, G.; Maeder, A. (2006). "The Effective Temperatures and Physical Properties of Magellanic Cloud Red Supergiants: The Effects of Metallicity". The Astrophysical Journal 645 (2): 1102. arXiv:astro-ph/0603596. Bibcode:2006ApJ...645.1102L. doi:10.1086/504417.  edit
  2. ^ a b c Arroyo-Torres, B.; Wittkowski, M.; Marcaide, J. M.; Hauschildt, P. H. (2013). "The atmospheric structure and fundamental parameters of the red supergiants AH Scorpii, UY Scuti, and KW Sagittarii". Astronomy & Astrophysics 554: A76. doi:10.1051/0004-6361/201220920.  edit
  3. ^ Zhang, B.; Reid, M. J.; Menten, K. M.; Zheng, X. W.; Brunthaler, A. (2012). "The distance and size of the red hypergiant NML Cygni from VLBA and VLA astrometry". Astronomy & Astrophysics 544: A42. arXiv:1207.1850. Bibcode:2012A&A...544A..42Z. doi:10.1051/0004-6361/201219587.  edit
  4. ^ Emily M. Levesque, Philip Massey, Bertrand Plez, and Knut A. G. Olsen (June 2009). "The Physical Properties of the Red Supergiant WOH G64: The Largest Star Known?". Astronomical Journal 137 (6): 4744. arXiv:0903.2260. Bibcode:2009AJ....137.4744L. doi:10.1088/0004-6256/137/6/4744. 
  5. ^ Wright, Nicholas J.; Roger Wesson; Drew, Janet E.; Geert Barentsen; Barlow, Michael J.; Walsh, Jeremy R.; Albert Zijlstra; Drake, Jeremy J. et al. (2013). "The Ionized Nebula surrounding the Red Supergiant W26 in Westerlund 1". arXiv:1309.4086v1 [astro-ph.SR].
  6. ^ Clark, J. S.; Ritchie, B. W.; Negueruela, I.; Crowther, P. A.; Damineli, A.; Jablonski, F. J.; Langer, N. (2011). "A VLT/FLAMES survey for massive binaries in Westerlund 1". Astronomy & Astrophysics 531: A28. arXiv:1105.0776. Bibcode:2011A&A...531A..28C. doi:10.1051/0004-6361/201116990.  edit
  7. ^ Clark, J. S.; Ritchie, B. W.; Negueruela, I. (2010). "A serendipitous survey for variability amongst the massive stellar population of Westerlund 1". Astronomy and Astrophysics 514: A87. arXiv:1003.5107. Bibcode:2010A&A...514A..87C. doi:10.1051/0004-6361/200913820.  edit
  8. ^ a b c d Nicolas Mauron; Eric Josselin (2010). "The mass-loss rates of red supergiants and the de Jager prescription". arXiv:1010.5369 [astro-ph.SR].
  9. ^ a b c d e f g h i j k l m n o p q r s t u Levesque, E. M.; Massey, P.; Olsen, K. A. G.; Plez, B.; Josselin, E.; Maeder, A.; Meynet, G. (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not as Cool as We Thought". The Astrophysical Journal 628 (2): 973. arXiv:astro-ph/0504337. Bibcode:2005ApJ...628..973L. doi:10.1086/430901.  edit
  10. ^ Wittkowski, M.; Hauschildt, P. H.; Arroyo-Torres, B.; Marcaide, J. M. (2012). "Fundamental properties and atmospheric structure of the red supergiant VY Canis Majoris based on VLTI/AMBER spectro-interferometry". Astronomy & Astrophysics 540: L12. arXiv:1203.5194. Bibcode:2012A&A...540L..12W. doi:10.1051/0004-6361/201219126.  edit
  11. ^ Choi, Yoon Kyung; Hirota, Tomoya; Honma, Mareki; Kobayashi, Hideyuki; Bushimata, Takeshi; Imai, Hiroshi; Iwadate, Kenzaburo; Jike, Takaaki; Kameno, Seiji; Kameya, Osamu; Kamohara, Ryuichi; Kan-Ya, Yukitoshi; Kawaguchi, Noriyuki; Kijima, Masachika; Kim, Mi Kyoung; Kuji, Seisuke; Kurayama, Tomoharu; Manabe, Seiji; Maruyama, Kenta; Matsui, Makoto; Matsumoto, Naoko; Miyaji, Takeshi; Nagayama, Takumi; Nakagawa, Akiharu; Nakamura, Kayoko; Oh, Chung Sik; Omodaka, Toshihiro; Oyama, Tomoaki; Sakai, Satoshi; Sasao, Tetsuo; Sato, Katsuhisa; Sato, Mayumi; Shibata, Katsunori M.; Tamura, Yoshiaki; Tsushima, Miyuki; Yamashita, Kazuyoshi (2008). "Distance to VY VMa with VERA". Publications of the Astronomical Society of Japan (Publications Astronomical Society of Japan) 60: 1007. arXiv:0808.0641. Bibcode:2008PASJ...60.1007C. 
  12. ^ Kusuno, K.; Asaki, Y.; Imai, H.; Oyama, T. (2013). "Distance and Proper Motion Measurement of the Red Supergiant, Pz Cas, in Very Long Baseline Interferometry H2O Maser Astrometry". The Astrophysical Journal 774 (2): 107. doi:10.1088/0004-637X/774/2/107.  edit
  13. ^ o. Chesneau; a. Meilland; e. Chapellier; f. Millour; a.m. Van Genderen; y. Naze; n. Smith; a. Spang; Et Al. (2014). "The yellow hypergiant HR 5171 A: Resolving a massive interacting binary in the common envelope phase". Astronomy & Astrophysics. doi:10.1051/0004-6361/201322421.  edit
  14. ^ Tsuji, Takashi (2000). "Water in Emission in the Infrared Space Observatory Spectrum of the Early M Supergiant Star μ Cephei". The Astrophysical Journal Letters 540 (2): 99–102. arXiv:astro-ph/0008058. Bibcode:2000ApJ...540L..99T. doi:10.1086/312879. 
  15. ^ Graham M. Harper et al. (2008). "A NEW VLA-HIPPARCOS DISTANCE TO BETELGEUSE AND ITS IMPLICATIONS". The Astronomical Journal 135 (4): 1430–1440. Bibcode:2008AJ....135.1430H. doi:10.1088/0004-6256/135/4/1430. 
  16. ^ "Big and Giant Stars"
  17. ^ http://www.eso.org/~mwittkow/publications/conferences/SPIECWo5491199.pdf
  18. ^ "The HST Treasury Program on Eta Carinae". Etacar.umn.edu. 2003-09-01. Retrieved 2012-10-14. 
  19. ^ Richichi, A.; Roccatagliata, V. (2005). "Aldebaran's angular diameter: how well do we know it?". Astronomy and Astrophysics 433: 305–312. arXiv:astro-ph/0502181. Bibcode:2005A&A...433..305R. doi:10.1051/0004-6361:20041765. 

External links[edit]