HD 152408
Star in the constellation of Scorpius
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HD 152408, also known as WR 79a, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 1,800 parsecs (6,000 light-years) away from the Earth.
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius[1] |
| Right ascension | 16h 54m 58.5051s[2] |
| Declination | −41° 09′ 03.093″[2] |
| Apparent magnitude (V) | 5.81 – 5.85[3] |
| Characteristics | |
| Evolutionary stage | Wolf–Rayet[4] |
| Spectral type | WN9ha[4] |
| U−B color index | −0.8[5] |
| B−V color index | 0.017[5] |
| Variable type | WR[3] |
| Astrometry | |
| Radial velocity (Rv) | −138[6] km/s |
| Proper motion (μ) | RA: +0.47[2] mas/yr Dec.: −2.25[2] mas/yr |
| Parallax (π) | 0.5417±0.0506 mas[2] |
| Distance | 6,000 ± 600 ly (1,800 ± 200 pc) |
| Absolute magnitude (MV) | −7.1[4] |
| Details | |
| Mass | 27.3[7] M☉ |
| Radius | 45[7] R☉ |
| Luminosity (bolometric) | 850,000[7] L☉ |
| Surface gravity (log g) | 3.32[8] cgs |
| Temperature | 35,481[7] K |
| Age | 4.8[9] Myr |
| Other designations | |
| HD 152408, WR 79a, HR 6272, HIP 82775, SAO 227425, CD−40°10919, Trumpler 24 159[10] | |
| Database references | |
| SIMBAD | data |
HD 152408 lies in the north of the open cluster NGC 6231, the center of the OB association Scorpius OB1; it is not clear whether it is a part of the association or not.[11] With an apparent magnitude of about 5.8, it is the third brightest Wolf-Rayet star and it can only be seen with the naked eye under excellent viewing conditions. The other Wolf-Rayet stars that can be seen with the naked eye are γ2 Velorum (WR 11), θ Muscae (WR 48), WR 22, WR 24 and HD 151932 (WR 78).
HD 152408 is over 20 times as massive as the Sun. Like most extremely massive stars, it is losing mass via its stellar wind. The total rate of mass loss is 2.4×10−5 M☉/yr. With an effective temperature of 35,000 K, its bolometric luminosity is more than 600,000 L☉.[12]