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″[1]
Apparent magnitude (V) 16.08[1]
Characteristics
Spectral type WN5h[1]
U−B color index -0.35
B−V color index -0.58[1]
Astrometry
Radial velocity (Rv) 300[1] km/s
Distance 164,000 ly
(50,000 pc)
Absolute magnitude (MV) -6.83±0.12[1]
Absolute bolometric
magnitude
 (Mbol)
-11.5
Details
Mass 150[1] M
Radius 22[1] R
Luminosity 3.2 million[1] L
Temperature 52,200±2500[1] K
Rotation 200[1]
Age 1.4 million[1] years

VFTS 682 is a Wolf-Rayet star in the Large Magellanic Cloud. [1] It is located in an active star-forming region, at a projected distance of approximately 29 pc northeast of the massive cluster R136 in the Tarantula Nebula. It is about 150 times the mass of the sun which makes it one of the most massive stars known. It is also one of the most luminous stars known at an estimated 3.2 million solar luminosities.[1]

Details[edit]

VFTS 682 is in a late stage of evolution, having a short time left before it explodes as a supernovae. When it evolved off the main sequence, it shed its hydrogen layers, leaving itself a hot core and turning into a WN5h Wolf-Rayet star. [1] The star's high mass compresses its core and ignites fusion using the CNO process which leads to an extremely high luminosity. The brightness of the star results in stellar winds with speeds up to 2600 km/s. [1] At 22 solar radii, the star is relatively small, but because of its high temperature, it shines at 3.2 million times brighter than the sun. [1] The velocity of the star and its close distance to R136 indicates that it could have formed inside R136, but then was ejected by a close stellar encounter. [1]

Eddington limit[edit]

The Eddington limit, which is a well known rule in astronomy, states that no star can have a mass over 150 M☉. It's assumed that VFTS 682's birth mass exceeded the Eddington limit since it would have shed much of that mass through stellar winds. [2] This suggests that the star formed through mergers of multiple stars.

Future[edit]

The star's stellar winds will shed most of its remaining layers and it will evolve into a WO oxygen-burning Wolf-Rayet star which will raise its temperature to 200,000 K. [3][4] Then it will develop an iron core and explode as a type Ic supernovae, leaving behind a black hole. The supernovae remnant left over from the explosion will seed its environment with heavy elements which will then enrich the next generation of stars, planets, and moons. The star's lifetime will be short, only 2 million years. Since its age is 1.4 million years, [1] the star is expected to explode as a supernovae in the astronomically near future.


See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q r s Bestenlehner, J. M.; et al. (May 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. 
  2. ^ Vink; Bestenlehner; Graefener; de Koter; Langer (2011). "Wind Models for Very Massive Stars in the Local Universe". arXiv:1112.0936v1 [astro-ph.SR].
  3. ^ Yusof, N.; Hirschi, R.; Meynet, G.; Crowther, P. A.; Ekstrom, S.; Frischknecht, U.; Georgy, C.; Abu Kassim, H.; Schnurr, O. (2013). "Evolution and fate of very massive stars". Monthly Notices of the Royal Astronomical Society 433 (2): 1114. doi:10.1093/mnras/stt794.  edit
  4. ^ Köhler, K.; Langer, N.; De Koter, A.; De Mink, S. E.; Crowther, P. A.; Evans, C. J.; Gräfener, G.; Sana, H.; Sanyal, D.; Schneider, F. R. N.; Vink, J. S. (2014). "The evolution of rotating very massive stars with LMC composition". Astronomy & Astrophysics 573: A71. doi:10.1051/0004-6361/201424356.  edit