VFTS 682
 VFTS 682 is at the very centre of this image of the Tarantula Nebula Credit: ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Dorado |
| Right ascension | 05h 38m 55.51s |
| Declination | −69° 04′ 26.72″ |
| Apparent magnitude (V) | 16.08 |
| Characteristics | |
| Spectral type | WN5h |
| U−B color index | -0.349 |
| B−V color index | -0.58 |
| Astrometry | |
| Radial velocity (Rv) | 300 km/s |
| Distance | 164,000 ly (50,000 pc) |
| Absolute magnitude (MV) | -6.83±0.12 |
| Absolute bolometric magnitude (Mbol) |
-11.5 |
| Details | |
| Mass | 150 M☉ |
| Radius | 22 R☉ |
| Luminosity | 3.2 million L☉ |
| Luminosity (visual, LV) | 43,000 L☉ |
| Temperature | 52,200±2,500 K |
| Rotation | <200 |
| Age | 1-1.4 million years |
| Other designations | |
| 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. 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.
VFTS 682 is a prominent infrared source in the Large Magellanic Cloud and has been catalogued numerous times. In 1992 it was identified as entry 153 in a list of possible protostars. In 2009 it was again classified as a probable young stellar object on account of its exceptional infrared luminosity.
The VLT-FLAMES Tarantula survey (VFTS) examined 800 massive stars in detail and determined a spectral type of WN5h for VFTS 682. It is heavily reddened and visually several magnitudes fainter than other stars of similar luminosity and temperature in the 30 Doradus region.
VFTS 682 is in the large star-forming region of the Tarantula Nebula, but is not within a dense massive cluster. The existence of an extremely massive and extremely young star in some isolation is unexpected since these stars are expected to form only from the most massive and dense molecular clouds and hence to form in large groups such as R136 as the result of competitive accretion or stellar mergers. The formation of isolated massive star would require different models to allow monolithic disk accretion of very massive stars.
VFTS 682 is close enough to R136 that it might have formed there and been ejected. No bow shock has been detected and it has a space velocity lower than most runaways, but large enough and in the right direction that it could be from R136.
The star's high mass of 150 M☉ compresses its core to a high temperature and causes very rapid fusion via the CNO cycle, leading to the extremely high luminosity of 3.2 million L☉. The star is 22 times the radius of the sun but because of its high temperature it emits 3.2 million times more energy, mostly at ultraviolet wavelengths so it is only 43,000 times as bright as the sun visually. Nearly 99% (AV = 4.5) of the ultraviolet and visual radiation is then blocked by intervening interstellar material. The luminosity, intense UV radiation, and chemical makeup of the star's surface layers results in a stellar wind with a speed up to 2,600 km/s (1,600 mi/s).
...
Wikipedia