  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 17h 46m 15.12s[1] |
| Declination | −28° 49′ 36.9″[1] |
| Characteristics | |
| Evolutionary stage | Wolf Rayet |
| Spectral type | WN9h[2] |
| Apparent magnitude (K) | 8.8[3] |
| Astrometry | |
| Radial velocity (Rv) | 116[4] km/s |
| Proper motion (μ) | RA: -0.59[1]mas/yr Dec.: -1.21[1]mas/yr |
| Distance | 26k[2] ly (8k[2] pc) |
| Details | |
| Mass | 58[5] M☉ |
| Radius | 86[2] R☉ |
| Luminosity | 2.5 million[2] L☉ |
| Temperature | 25,100[2] K |
| Age | ~4[5] Myr |
| Other designations | |
| FMM 241, qF 241, (erroneously QPM-241), Q10, MGM 5-10, LHO 71 | |
| Database references | |
| SIMBAD | data |
WR 102ea is aWolf–Rayet star in theSagittarius constellation. It is the third most luminous star in theQuintuplet Cluster afterWR 102hb. With aluminosity of 2,500,000 timessolar, it is also one of themost luminous stars known. Despite the high luminosity it can only be observed atinfra-red wavelengths due to the dimming effect of intervening dust on visual light.
It is an evolved massive star which has an emission line spectrum from a strong stellar wind caused by high luminosity and the presence of elements heavier than hydrogen in thephotosphere. The spectrum is dominated by ionisedhelium andnitrogen lines due to convectional and rotational mixing of fusion products to the surface of the star. However it is still in a corehydrogen burning phase and hydrogen lines are also visible in the spectrum, in contrast to WN stars without hydrogen which are older, less massive, and less luminous. Despite being a relatively unevolved star, WR 102ea has lost over half its mass already.[5]
