WR 119
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Scutum |
| Right ascension | 18h 39m 17.904s |
| Declination | −10° 50′ 30.90″ |
| Apparent magnitude (V) | 12.06 |
| Characteristics | |
| Evolutionary stage | Wolf-Rayet |
| Spectral type | WC9d |
| B−V color index | +0.93 |
| Astrometry | |
| Proper motion (μ) | RA: −1.223 mas/yr Dec.: −5.285 mas/yr |
| Parallax (π) | 0.2098±0.0155 mas |
| Distance | 3,220+1,240 −730 pc |
| Absolute magnitude (MV) | −3.91 |
| Details | |
| Mass | 5.8 M☉ |
| Radius | 3.7 R☉ |
| Luminosity | 50,100 L☉ |
| Temperature | 45,000 K |
| Other designations | |
| WR 119, 2MASS J18391789-1005309 | |
| Database references | |
| SIMBAD | data |
WR 119 is a Wolf–Rayet star located about 10,500 light years away in the constellation Scutum. WR 119 is classified as a WC9 star, belonging to the late-type carbon sequence of Wolf-Rayet stars. WR 119 is noteworthy for being the least luminous known Wolf-Rayet star, at just over 50,000 L☉. The most recent estimate is even lower, at just 42,700 L☉, based on the most recent analysis using Gaia DR2 data.
Properties
WR 119's properties are on the very edge of what may be possible for Wolf-Rayet stars, due to being so extremely dim. Modelling its spectrum using PoWR gives a temperature of 45,000 K. Factoring in the distance used in that study of 3,500 pc, WR 119's luminosity is only 50,100 L☉, derived from Gaia DR2's parallax data. The corresponding radius is only 3.7 R☉, the smallest of the WC9 stars, less than half the size of the average WC9 star. WR 119's luminosity is also just 20% that of the average WC9 star's luminosity. The corresponding mass is just 5.8 M☉, the lowest mass for any Wolf-Rayet star derived using a mass-luminosity relation.
In the visual wavelength, the star is also the dimmest of the WC9 stars (and anything later than WC4 in the study), with a visual luminosity of just 3,130 L☉ because most of the 50,100 L☉ is emitted at ultraviolet wavelengths due to WR 119's very high surface temperature.
WR 119 has a strong stellar wind, typical of Wolf-Rayet stars, but weaker than most WC stars. WR 119 loses 10−5.13 M☉ (about 7.41×10−6 M☉) per year because of this stellar wind, which has a terminal velocity of 1,300 kilometres per second. WR 119 also emits a lot of dust, hence the "d" at the end of its spectral type, which may be an indication of binary status.
