R136b

R136b is a Wolf-Rayet star in the R136 cluster in the Large Magellanic Cloud.[4] It is one of the most massive and most luminous stars known. It is found in the dense R136 open cluster at the centre of NGC 2070 in the Tarantula Nebula.

R136b

R136b is the bright star towards the lower left.
Credit: ESO
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Dorado
Right ascension  05h 38m 42.74s[1]
Declination −69° 06 03.78[1]
Apparent magnitude (V) 13.24[1]
Characteristics
Spectral type O4If/WN8[2]
B−V color index −0.18[1]
Astrometry
Distance163,000 ly
(49,970[3] pc)
Absolute magnitude (MV)7.31[2]
Details[2]
Mass93 M
Radius22.3[4] R
Luminosity1,995,000 L
Temperature41,000 K
Age1.5 Myr
Other designations
BAT99 111, RMC 136b, [HSH95] 9, [WO84] 4, NGC 2070 MH 637, [CHH92] 26, [P93] 985.
Database references
SIMBADdata

R136b has a transitional spectral type between an O class supergiant and a Wolf-Rayet star, with a mix of absorption and emission lines. Although it shows enhanced helium and nitrogen at its surface, it is still a very young star, still burning hydrogen in its core via the CNO cycle, and still effectively a main sequence object.[5]

References

  1. Doran, E. I.; Crowther, P. A.; De Koter, A.; Evans, C. J.; McEvoy, C.; Walborn, N. R.; Bastian, N.; Bestenlehner, J. M.; Gräfener, G.; Herrero, A.; Köhler, K.; Maíz Apellániz, J.; Najarro, F.; Puls, J.; Sana, H.; Schneider, F. R. N.; Taylor, W. D.; Van Loon, J. Th.; Vink, J. S. (2013). "The VLT-FLAMES Tarantula Survey. XI. A census of the hot luminous stars and their feedback in 30 Doradus". Astronomy & Astrophysics. 558: A134. arXiv:1308.3412. Bibcode:2013A&A...558A.134D. doi:10.1051/0004-6361/201321824.
  2. Crowther, Paul A.; Caballero-Nieves, S. M.; Bostroem, K. A.; Maíz Apellániz, J.; Schneider, F. R. N.; Walborn, N. R.; Angus, C. R.; Brott, I.; Bonanos, A.; De Koter, A.; De Mink, S. E.; Evans, C. J.; Gräfener, G.; Herrero, A.; Howarth, I. D.; Langer, N.; Lennon, D. J.; Puls, J.; Sana, H.; Vink, J. S. (2016). "The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of He II λ1640 in young star clusters". Monthly Notices of the Royal Astronomical Society. 458 (1): 624–659. arXiv:1603.04994. Bibcode:2016MNRAS.458..624C. doi:10.1093/mnras/stw273.
  3. Pietrzyński, G; D. Graczyk; W. Gieren; I. B. Thompson; B. Pilecki; A. Udalski; I. Soszyński; et al. (7 March 2013). "An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent". Nature. 495 (7439): 76–79. arXiv:1303.2063. Bibcode:2013Natur.495...76P. doi:10.1038/nature11878. PMID 23467166.
  4. Hainich, R.; Rühling, U.; Todt, H.; Oskinova, L. M.; Liermann, A.; Gräfener, G.; Foellmi, C.; Schnurr, O.; Hamann, W. -R. (2014). "The Wolf-Rayet stars in the Large Magellanic Cloud". Astronomy & Astrophysics. 565: A27. arXiv:1401.5474. Bibcode:2014A&A...565A..27H. doi:10.1051/0004-6361/201322696.
  5. Crowther, Paul A.; Schnurr, Olivier; Hirschi, Raphael; Yusof, Norhasliza; Parker, Richard J.; Goodwin, Simon P.; Kassim, Hasan Abu (2010). "The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150Msolar stellar mass limit". Monthly Notices of the Royal Astronomical Society. 408 (2): 731. arXiv:1007.3284. Bibcode:2010MNRAS.408..731C. doi:10.1111/j.1365-2966.2010.17167.x.
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