HD 70930
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vela |
| Right ascension | 08h 22m 31.6941s |
| Declination | −48° 29′ 25.3631″ |
| Apparent magnitude (V) | 4.79 (5.14 + 6.08) |
| Characteristics | |
| Spectral type | B1V or B2III |
| B−V color index | −0.146±0.002 |
| Astrometry | |
| Radial velocity (Rv) | +27.0±4.5 km/s |
| Proper motion (μ) | RA: −5.10±0.39 mas/yr Dec.: +7.76±0.33 mas/yr |
| Parallax (π) | 1.90±0.32 mas |
| Distance | approx. 1,700 ly (approx. 530 pc) |
| Absolute magnitude (MV) | −3.74 |
| Details | |
| Mass | 15.6±0.8 M☉ |
| Radius | 13.6 R☉ |
| Luminosity | 20,893 L☉ |
| Surface gravity (log g) | 2.74 cgs |
| Temperature | 23,532 K |
| Rotational velocity (v sin i) | 220 km/s |
| Age | 10.0±0.1 Myr |
| Other designations | |
| I 67, B Velorum, CD−48°3734, HD 70930, HIP 41039, HR 3294, SAO 219848, CCDM 08225-4829, WDS J08225-4829AB | |
| Database references | |
| SIMBAD | data |
HD 70930 is a binary star system in the southern constellation of Vela. It has the Bayer designation B Velorum, while HD 70930 is the star's identifier in the Henry Draper catalogue. With a combined apparent visual magnitude of 4.79, it is visible to the naked eye as a faint point of light. The distance to this system is approximately 1,700 light years based on parallax, and it has an absolute magnitude of −3.74. It is drifting further away from the Sun with a radial velocity of about +27 km/s. The system is a member of the Vel OB2 association of co-moving stars.
The double nature of this system was discovered in 1896 by Scottish astronomer Robert T. A. Innes – it is now known to be a double-lined spectroscopic binary. The magnitude 5.14 primary component has a blue-white hue and has been assigned stellar classifications of B1V and B2III, matching a B-type main-sequence star or a giant star, respectively. It is a massive object – over 15 times the mass of the Sun – and is around 10 million years old. The star has a high rate of spin, showing a projected rotational velocity of 220 km/s. Its companion, at magnitude +6.08, is located at an angular separation of 0.8″ along a position angle of 139°, as of 2008.