| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 12h 08m 05.22401s [2] |
| Declination | −50° 39′ 40.5728″ [2] |
| Apparent magnitude (V) | 4.47 [3] |
| Characteristics | |
| Spectral type | B6III [4] |
| U−B color index | −0.67 [3] |
| B−V color index | −0.15 [3] |
| Variable type | rotating variable [5] |
| Astrometry | |
| Radial velocity (Rv) | 16.5 [3] km/s |
| Proper motion (μ) |
RA: −35.16
[2]
mas/
yr Dec.: −6.47 [2] mas/ yr |
| Parallax (π) | 7.44 ± 0.61 mas [2] |
| Distance | 440 ± 40
ly (130 ± 10 pc) |
| Absolute magnitude (MV) | −1.2±0.3 [4] |
|
Absolute bolometric magnitude (Mbol) | −2.9 ± 0.4 [4] |
| Details | |
| Mass | 5.7 ± 0.4 [5] M☉ |
| Radius | 3.0 ± 0.6 [5] R☉ |
| Luminosity | 1000+590 −370 [4] L☉ |
| Surface gravity (log g) | 4.18 ± 0.15 [5] cgs |
| Temperature | 17400 ± 400 [5] K |
| Rotation | 1.295 ± 0.001 [5] days |
| Rotational velocity (v sin i) | 90 [4] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 105382 (also known as V863 Centauri) is a star in the constellation Centaurus. Its apparent magnitude is 4.47. From parallax measurements, it is located 130 parsecs (440 light years) from the Sun.
HD 105382 is a variable star whose apparent magnitude varies with an amplitude of 0.012 over a period of 1.295 days. It has been previously classified as a Be star, which would explain the variability as stellar pulsations, but this classification was probably due to accidental observation of the nearby Be star δ Centauri. [6] A 2004 study showed that the 1.295 day period is actually the rotation period of the star, and that the variability is caused by non-homogeneous distribution of elements in the stellar surface. In particular, HD 105382 is a helium-weak chemically peculiar star with a helium abundance varying between 0.5% and 15% of the solar abundance, and a silicon abundance varying between 0.00044% and 0.0069% the solar value. Regions with more helium appear to coincide with the regions with less silicon, and vice versa. [5] This peculiar abundance pattern is probably related to HD 105382's magnetic field, [5] which has a polar strength of 2.3 kG. [4]
From astrometric measurements by the Hipparcos spacecraft, HD 105382 is identified as a probable astrometric binary. [7] It is only 267" away from δ Centauri, and both stars appear to be at the same distance from Earth and have the same motion through space, so they may be related. In total, this may be a five star system. [8] It is a member of the Lower Centaurus–Crux (LCC) subgroup of the Scorpius–Centaurus association. [9]
References
- ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
- ^ a b c d e 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, S2CID 18759600.
- ^ a b c d e "HD 105382". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 October 2017.
- ^ a b c d e f Petit, V.; et al. (February 2013), "A magnetic confinement versus rotation classification of massive-star magnetospheres", Monthly Notices of the Royal Astronomical Society, 429 (1): 398–422, arXiv: 1211.0282, Bibcode: 2013MNRAS.429..398P, doi: 10.1093/mnras/sts344, S2CID 14961579.
- ^ a b c d e f g h Briquet, M.; et al. (January 2004). "He and Si surface inhomogeneities of four Bp variable stars". Astronomy and Astrophysics. 413: 273–283. Bibcode: 2004A&A...413..273B. doi: 10.1051/0004-6361:20031450.
- ^ Briquet, M.; Aerts, C.; De Cat, P. (January 2001). "Optical variability of the B-type star HD 105382: Pulsation or rotation?". Astronomy and Astrophysics. 366: 121–128. Bibcode: 2001A&A...366..121B. doi: 10.1051/0004-6361:20000193.
- ^ Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal, 129 (5): 2420–2427, Bibcode: 2005AJ....129.2420M, doi: 10.1086/429590.
- ^ 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, arXiv: 0806.2878, Bibcode: 2008MNRAS.389..869E, doi: 10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ de Geus, E. J.; de Zeeuw, P. T.; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics, 216 (1–2): 44–61, Bibcode: 1989A&A...216...44D
