Astronomy:V831 Centauri
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 12m 17.59459s[2] |
| Declination | −59° 55′ 14.0842″[2] |
| Apparent magnitude (V) | 4.58[3] (4.49 to 4.66)[4] |
| Characteristics | |
| Spectral type | B7V[5] (B8V + ? + B9V)[6] |
| B−V color index | −0.073±0.007[3] |
| Variable type | Rotating ellipsoidal[4] |
| Astrometry | |
| Radial velocity (Rv) | +12.0±3.7[3] km/s |
| Proper motion (μ) | RA: −29.71[2] mas/yr Dec.: −17.40[2] mas/yr |
| Parallax (π) | 8.61 ± 0.85[2] mas |
| Distance | 380 ± 40 ly (120 ± 10 pc) |
| Absolute magnitude (MV) | −0.72[3] |
| Orbit[7] | |
| Primary | A |
| Companion | B |
| Period (P) | 27.2±0.4 yr |
| Semi-major axis (a) | 180±20 mas |
| Eccentricity (e) | 0.48±0.1 |
| Inclination (i) | 62.2±2.0° |
| Longitude of the node (Ω) | −104±5° |
| Periastron epoch (T) | 1887.2±0.6 |
| Argument of periastron (ω) (secondary) | 219±5° |
| Orbit[7] | |
| Primary | AB |
| Companion | C |
| Period (P) | ~2,000 yr |
| Semi-major axis (a) | 3.2±0.1″ |
| Eccentricity (e) | 0.5 |
| Inclination (i) | 68° |
| Longitude of the node (Ω) | −85° |
| Periastron epoch (T) | 1084.5±3.0 |
| Details[7] | |
| Aa | |
| Mass | 4.08±0.07 M☉ |
| Radius | 2.38±0.03 R☉ |
| Luminosity | 261.12[3] L☉ |
| Temperature | 13,000±300 K |
| Rotational velocity (v sin i) | 194 km/s |
| Ab | |
| Mass | 3.35±0.06 M☉ |
| Radius | 2.25±0.03 R☉ |
| Temperature | 11,800±300 K |
| Rotational velocity (v sin i) | 170 km/s |
| Age | 18±3 Myr |
| B | |
| Mass | 2.5 M☉ |
| C | |
| Mass | 1.5 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
V831 Centauri is a multiple[6] star system in the constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude that ranges from 4.49 down to 4.66.[4] The system is located at a distance of approximately 380 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s.[3] It is a likely member of the Lower Centaurus Crux concentration of the Sco OB2 association of co-moving stars.
The magnitude 5.3 primary component forms a near-contact binary system, with the components designated Aa and Ab. It has a combined class of B8V, an orbital period of 0.6425251 d, a separation of 6 R☉, and both components are close to co-rotating with their orbit. The larger member has 4.1 times the mass of the Sun and 2.4 times the Sun's radius, while the companion has 3.4 and 2.3 times, respectively. The pair form an eclipsing system,[7] and it is classed as a rotating ellipsoidal variable.[4]
The third star, component B, is magnitude 6.0 and forms a visual pair, designated See 170, with the inner system. They orbit each other with a period of 27.2 years and an eccentricity of 0.5. This star has a mass about 2.5 times that of the Sun and may be an Ap star. The fourth member, component C, orbits the system with a period of around 2,000 years. There is a fifth member, component D.[7]
References
- ↑ "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access.
- ↑ 2.0 2.1 2.2 2.3 2.4 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.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 4.0 4.1 4.2 4.3 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ 6.0 6.1 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ 7.0 7.1 7.2 7.3 7.4 Budding, E.; Erdem, A.; Inlek, G.; Demircan, O. (April 2010), "Absolute parameters of young stars - II. V831 Centauri", Monthly Notices of the Royal Astronomical Society 403 (3): 1448–1456, doi:10.1111/j.1365-2966.2010.16209.x, Bibcode: 2010MNRAS.403.1448B.
- ↑ "V831 Cen". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V831+Cen.
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