Astronomy:R136b

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Short description: Star in the constellation Dorado
R136b
R136a1 star.jpg
R136b is the bright star towards the lower left.
Credit: ESO
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
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[2]
B−V color index −0.18[1]
Astrometry
Distance163,000 ly
(49,970[3] pc)
Absolute magnitude (MV)−7.75[2]
Details[2]
Mass117+91
−51
 M
Radius40.0 R
Luminosity2,188,000 L
Surface gravity (log g)3.30±0.25 cgs
Temperature35,000±2,500 K
Rotational velocity (v sin i)85 km/s
Age1.7±0.2 Myr
Other designations
BAT99 111, RMC 136b, [HSH95] 9, [WO84] 4, NGC 2070 MH 637, [CHH92] 26, [P93] 985.
Database references
SIMBADdata

R136b is a blue supergiant star in the R136 cluster in the Large Magellanic Cloud. 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 has the spectral type of Wolf–Rayet star, with strong emission lines.[4] 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] Others studies classify the spectrum as a hot supergiant with emission lines of ionised nitrogen and helium, still considering it to be a young star at the core-hydrogen-burning stage, the unusual spectrum caused by strong convection and stellar winds.[2]

References

  1. 1.0 1.1 1.2 1.3 Doran, E. I.; Crowther, P. A.; De Koter, A.; Evans, C. J.; McEvoy, C.; Walborn, N. R.; Bastian, N.; Bestenlehner, J. M. et al. (2013). "The VLT-FLAMES Tarantula Survey. XI. A census of the hot luminous stars and their feedback in 30 Doradus". Astronomy & Astrophysics 558: A134. doi:10.1051/0004-6361/201321824. Bibcode2013A&A...558A.134D. 
  2. 2.0 2.1 2.2 2.3 Bestenlehner, Joachim M.; Crowther, Paul A.; Caballero-Nieves, Saida M.; Schneider, Fabian R. N.; Simón-Díaz, Sergio; Brands, Sarah A.; De Koter, Alex; Gräfener, Götz et al. (2020). "The R136 star cluster dissected with Hubble Space Telescope/STIS. II. Physical properties of the most massive stars in R136". Monthly Notices of the Royal Astronomical Society 499 (2): 1918. doi:10.1093/mnras/staa2801. Bibcode2020MNRAS.499.1918B. 
  3. Pietrzyński, G et al. (7 March 2013). "An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent". Nature 495 (7439): 76–79. doi:10.1038/nature11878. PMID 23467166. Bibcode2013Natur.495...76P. 
  4. Hainich, R.; Rühling, U.; Todt, H.; Oskinova, L. M.; Liermann, A.; Gräfener, G.; Foellmi, C.; Schnurr, O. et al. (2014). "The Wolf–Rayet stars in the Large Magellanic Cloud". Astronomy & Astrophysics 565: A27. doi:10.1051/0004-6361/201322696. Bibcode2014A&A...565A..27H. 
  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. doi:10.1111/j.1365-2966.2010.17167.x. Bibcode2010MNRAS.408..731C.