Astronomy:HD 105382
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[2] mas |
| 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". 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 "HD 105382". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+105382.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 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, doi:10.1093/mnras/sts344, Bibcode: 2013MNRAS.429..398P.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Briquet, M. (January 2004). "He and Si surface inhomogeneities of four Bp variable stars". Astronomy and Astrophysics 413: 273–283. doi:10.1051/0004-6361:20031450. Bibcode: 2004A&A...413..273B.
- ↑ 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. doi:10.1051/0004-6361:20000193. Bibcode: 2001A&A...366..121B.
- ↑ Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal 129 (5): 2420–2427, doi:10.1086/429590, Bibcode: 2005AJ....129.2420M.
- ↑ 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.
- ↑ 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
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