HD 152408

HD 152408
Location of WR 79a (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 16h 54m 58.5051s
Declination −41° 09 03.093
Apparent magnitude (V) 5.81  5.85
Characteristics
Spectral type WN9ha
U−B color index −0.8
B−V color index 0.017
Variable type WR
Astrometry
Radial velocity (Rv)−138 km/s
Proper motion (μ) RA: +0.47 mas/yr
Dec.: −2.25 mas/yr
Parallax (π)0.5417±0.0506 mas
Distance6,000 ± 600 ly
(1,800 ± 200 pc)
Absolute magnitude (MV)−7.1
Details
Mass27.3 M
Radius45 R
Luminosity (bolometric)850,000 L
Surface gravity (log g)3.32 cgs
Temperature35,481 K
Age4.8 Myr
Other designations
HD 152408, WR 79a, HR 6272, HIP 82775, SAO 227425, CD−40°10919, Trumpler 24 159
Database references
SIMBADdata

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.

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. With an apparent magnitude of about 5.8, it is the third brightest Wolf-Rayet star. The other Wolf-Rayet stars that can be seen with the naked eye (although it can only be seen with the naked eye under excellent viewing conditions) 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.