HD 85622
Binary star system in the constellation Vela / From Wikipedia, the free encyclopedia
HD 85622 is a binary star system in the southern constellation of Vela. It is visible to the naked eye with an apparent visual magnitude of 4.58.[2] The distance to HD 85622 can be estimated from its annual parallax shift of 4.3 mas,[1] yielding a value of 750 light years. It is moving further from the Earth with a heliocentric radial velocity of +8 km/s.[6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Vela |
Right ascension | 09h 51m 40.66782s[1] |
Declination | −46° 32′ 51.4329″[1] |
Apparent magnitude (V) | 4.58[2] |
Characteristics | |
Evolutionary stage | supergiant[3] |
Spectral type | G5 Ib[3] or G6 IIa[4] |
B−V color index | 1.20[5] |
Astrometry | |
Radial velocity (Rv) | +7.8±3.2[6] km/s |
Proper motion (μ) | RA: −24.784[1] mas/yr Dec.: +9.843[1] mas/yr |
Parallax (π) | 4.3323 ± 0.1445 mas[1] |
Distance | 750 ± 30 ly (231 ± 8 pc) |
Absolute magnitude (MV) | −2.96[2] |
Orbit[3] | |
Period (P) | 329.266±0.085 d |
Eccentricity (e) | 0 (adopted) |
Periastron epoch (T) | 2453860.281±0.074 HJD |
Semi-amplitude (K1) (primary) | 13.021±0.012 km/s |
Details | |
Mass | 6.2±0.5[7] M☉ |
Luminosity | 1908.45[8] L☉ |
Temperature | 4,796[8] K |
Rotational velocity (v sin i) | 19.3±1.0[5] km/s |
Age | 63.7±15.8[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
This is a single-lined spectroscopic binary with a circular orbit and a period of 329.3 days. The a sin i value is 0.39 AU, where a is the semimajor axis and i is the orbital inclination to the line of sight.[3] This value provides a lower bound on the actual semimajor axis. The system shows a micro-variability in its brightness,[3] and is a source of X-ray emission with an apparent flux of 42.6×10−17 W/m2.[10]
The visible component is a supergiant star with a stellar classification of G5 Ib[3] or G6 IIa.[4] It is about 64[7] million years old with a projected rotational velocity of 19 km/s.[5] The star has 6.2[7] times the mass of the Sun and is radiating 1,908[8] times the Sun's luminosity from its photosphere at an effective temperature of 4,796 K.[8]