VFTS 682

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VFTS 682
The brilliant star VFTS 682 in the Large Magellanic Cloud.jpg
VFTS 682 in the Large Magellanic Cloud
Observation data
Epoch J2000      Equinox J2000
Constellation Dorado
Right ascension 05h 38m 55.51s
Declination −69° 04′ 26.72″
Apparent magnitude (V) 16.08[1]
Characteristics
Spectral type WN5h[2]
U−B color index -0.35[citation needed]
B−V color index -0.58[1]
Astrometry
Radial velocity (Rv) 300[3] km/s
Distance 164,000 ly
(50,000 pc)
Absolute magnitude (MV) -6.83±0.12[3]
Absolute bolometric
magnitude
 (Mbol)
-11.5
Details
Mass 150[3] M
Radius 22[3] R
Luminosity 3.2 million[3] L
Luminosity (visual, LV) 43,000 L
Temperature 52,200±2,500[3] K
Rotation <200[4]
Age 1-1.4 million[3] years
Other designations
IRSF J05385552-6904267, DENIS J053855.4-690425, 2MASS J05385552-6904267, GC2009 J053855.56-690426.5, DENIS J053855.5-690426, Dor IRS 153, VFTS 682, P93 1732
Database references
SIMBAD data

VFTS 682 is a Wolf–Rayet star in the Large Magellanic Cloud. It is located over 29 parsecs (95 ly) north-east of the massive cluster R136 in the Tarantula Nebula.[3] It is 150 times the mass of the sun and 3.2 million times more luminous which makes it one of the most massive and most luminous stars known.

Details[edit]

The star's high mass of 150 M compresses its core and ignites fusion using the CNO cycle which leads to an extremely high luminosity of 3.2 million L. It is only 43,000 L in the visual band because of its high temperature. The brightness of the star results in a stellar wind with a speed up to 2,600 km/s (1,600 mi/s). The star is 22 times the radius of the sun but because of its high temperature it emits 3.2 million times more energy. The velocity of the star and its close distance to R136 indicates that it may have formed inside R136 but was ejected by a close stellar encounter.[5]

Evolution[edit]

Stars as massive as VFTS 682 with metallicity typical of the Large Magellanic Cloud will maintain near-homogeneous chemical structure due to strong convection and rotational mixing. This produces strong helium and nitrogen surface abundance enhancement even during core hydrogen burning. Their rotation rates will also decrease significantly due to mass loss and envelope inflation, so that gamma-ray bursts are unlikely when this type of star reaches core collapse. They are expected to develop directly into Wolf–Rayet stars, passing through WN, WC, and WO stages before exploding as a type Ic supernova and leaving behind a black hole. The total lifetime would be around 2 million years, showing an O-type spectrum for most of that time before a shorter period with a WR spectrum.[6][7]

References[edit]

  1. ^ a b Evans, C. J.; Taylor, W. D.; Hénault-Brunet, V.; Sana, H.; De Koter, A. et al. (June 2011). "The VLT-FLAMES Tarantula Survey. I. Introduction and observational overview". Astronomy & Astrophysics 530. A108. arXiv:1103.5386. Bibcode:2011A&A...530A.108E. doi:10.1051/0004-6361/201116782. 
  2. ^ Bressert, E.; Bastian, N.; Evans, C. J.; Sana, H.; Hénault-Brunet, V. et al. (June 2012). "The VLT-FLAMES Tarantula Survey. IV. Candidates for isolated high-mass star formation in 30 Doradus". Astronomy & Astrophysics 542. A49. arXiv:1204.3628. Bibcode:2012A&A...542A..49B. doi:10.1051/0004-6361/201117247. 
  3. ^ a b c d e f g h Bestenlehner, J. M.; Vink, J. S.; Gräfener, G.; Najarro, F.; Evans, C. J. et al. (June 2011). "The VLT-FLAMES Tarantula Survey. III. A very massive star in apparent isolation from the massive cluster R136". Astronomy & Astrophysics 530. L14. arXiv:1105.1775. Bibcode:2011A&A...530L..14B. doi:10.1051/0004-6361/201117043. 
  4. ^ Bestenlehner, J. M.; Gräfener, G.; Vink, Jorick S.; Najarro, F.; De Koter, A. et al. (October 2014). "The VLT-FLAMES Tarantula Survey. XVII. Physical and wind properties of massive stars at the top of the main sequence". Astronomy & Astrophysics 570. A38. doi:10.1051/0004-6361/201423643. 
  5. ^ Banerjee, S.; Kroupa, P.; Oh, S. (February 2012). "Runaway Massive Stars from R136: VFTS 682 is Very Likely a "Slow Runaway"". The Astrophysical Journal 746 (1). 15. arXiv:1111.0291. Bibcode:2012ApJ...746...15B. doi:10.1088/0004-637X/746/1/15. 
  6. ^ Yusof, N.; Hirschi, R.; Meynet, G.; Crowther, P. A.; Ekstrom, S. et al. (August 2013). "Evolution and fate of very massive stars". Monthly Notices of the Royal Astronomical Society 433 (2): 1114–1132. arXiv:1305.2099. Bibcode:2013MNRAS.433.1114Y. doi:10.1093/mnras/stt794. 
  7. ^ Köhler, K.; Langer, N.; De Koter, A.; De Mink, S. E.; Crowther, P. A. et al. (January 2015). "The evolution of rotating very massive stars with LMC composition". Astronomy & Astrophysics 573. A71. arXiv:1501.03794. Bibcode:2015A&A...573A..71K. doi:10.1051/0004-6361/201424356.