Astronomy:HD 70930
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Vela[1] |
| Right ascension | 08h 22m 31.6941s[2] |
| Declination | −48° 29′ 25.3631″[2] |
| Apparent magnitude (V) | 4.79[1] (5.14 + 6.08)[3] |
| Characteristics | |
| Spectral type | B1V[4] or B2III[5] |
| B−V color index | −0.146±0.002[1] |
| Astrometry | |
| Radial velocity (Rv) | +27.0±4.5[1] km/s |
| Proper motion (μ) | RA: −5.10±0.39[2] mas/yr Dec.: +7.76±0.33[2] mas/yr |
| Parallax (π) | 1.90 ± 0.32[2] mas |
| Distance | approx. 1,700 ly (approx. 530 pc) |
| Absolute magnitude (MV) | −3.74[1] |
| Details | |
| Mass | 15.6±0.8[4] M☉ |
| Radius | 13.6[6] R☉ |
| Luminosity | 20,893[7] L☉ |
| Surface gravity (log g) | 2.74[6] cgs |
| Temperature | 23,532[7] K |
| Rotational velocity (v sin i) | 220[7] km/s |
| Age | 10.0±0.1[4] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 70930 is a binary star[9] 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,[1] 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,[2] and it has an absolute magnitude of −3.74.[1] It is drifting further away from the Sun with a radial velocity of about +27 km/s.[1] The system is a member of the Vel OB2 association of co-moving stars.[10]
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.[11] 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 220 km/s.[7] 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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 3.0 3.1 3.2 3.3 3.4 Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M
- ↑ 4.0 4.1 4.2 4.3 4.4 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ 5.0 5.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ 6.0 6.1 McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society 471 (1): 770. doi:10.1093/mnras/stx1433. Bibcode: 2017MNRAS.471..770M.
- ↑ 7.0 7.1 7.2 7.3 Balona, L. A.; Ozuyar, D. (2020). "Pulsation among TESS a and B stars and the Maia variables". Monthly Notices of the Royal Astronomical Society 493 (4): 5871. doi:10.1093/mnras/staa670. Bibcode: 2020MNRAS.493.5871B.
- ↑ "HD 70930". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+70930.
- ↑ 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ de Zeeuw, P. T. et al. (January 1999), "A HIPPARCOS Census of the Nearby OB Associations", The Astronomical Journal 117 (1): 354–399, doi:10.1086/300682, Bibcode: 1999AJ....117..354D.
- ↑ 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, doi:10.1111/j.1365-2966.2012.21317.x, Bibcode: 2012MNRAS.424.1925C.
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