HD 70930 is a binary star[8] 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,[2] 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,[1] and it has an absolute magnitude of −3.74.[2] It is drifting further away from the Sun with a radial velocity of about +27 km/s.[2] The system is a member of the Vel OB2 association of co-moving stars.[9]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vela |
| Right ascension | 08h 22m 31.6941s[1] |
| Declination | −48° 29′ 25.3631″[1] |
| Apparent magnitude (V) | 4.79[2] (5.14 + 6.08)[3] |
| Characteristics | |
| Spectral type | B1V[4] or B2III[5] |
| B−V color index | −0.146±0.002[2] |
| Astrometry | |
| Radial velocity (Rv) | +27.0±4.5[2] km/s |
| Proper motion (μ) | RA: −5.10±0.39[1] mas/yr Dec.: +7.76±0.33[1] mas/yr |
| Parallax (π) | 1.90 ± 0.32 mas[1] |
| Distance | approx. 1,700 ly (approx. 530 pc) |
| Absolute magnitude (MV) | −3.74[2] |
| Details | |
| Mass | 15.6±0.8[4] M☉ |
| Luminosity | 6,833.12[2] L☉ |
| Rotational velocity (v sin i) | 169[6] km/s |
| Age | 10.0±0.1[4] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The double nature of this system was discovered in 1896 by Scottish astronomer Robert T. A. Innes[3] – it is now known to be a double-lined spectroscopic binary.[10] The magnitude 5.14[3] primary component has a blue-white hue and has been assigned stellar classifications of B1V[4] and B2III,[5] 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.[4] The star has a high rate of spin, showing a projected rotational velocity of 169 km/s.[6] Its companion, at magnitude +6.08, is located at an angular separation of 0.8″ along a position angle of 139°, as of 2008.[3]
References
edit- ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- ^ a b c d e f g h Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
- ^ a b c d e Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ a b Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
- ^ "HD 70930". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-10-06.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ de Zeeuw, P. T.; et al. (January 1999), "A HIPPARCOS Census of the Nearby OB Associations", The Astronomical Journal, 117 (1): 354–399, arXiv:astro-ph/9809227, Bibcode:1999AJ....117..354D, doi:10.1086/300682, S2CID 16098861.
- ^ Chini, R.; et al. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", Monthly Notices of the Royal Astronomical Society, 424 (3): 1925–1929, arXiv:1205.5238, Bibcode:2012MNRAS.424.1925C, doi:10.1111/j.1365-2966.2012.21317.x, S2CID 119120749.