Astronomy:Beta Sextantis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Sextans |
| Right ascension | 10h 30m 17.48s[1] |
| Declination | −00° 38′ 13.30″[1] |
| Apparent magnitude (V) | 5.07[2] |
| Characteristics | |
| Spectral type | B6 V[3] or B5 IV/V[4] |
| U−B color index | −0.51[2] |
| B−V color index | −0.14[2] |
| Variable type | α2 CVn[5] |
| Astrometry | |
| Radial velocity (Rv) | 11.6±2.8[6] km/s |
| Proper motion (μ) | RA: −38.805[1] mas/yr Dec.: −24.290[1] mas/yr |
| Parallax (π) | 8.9613 ± 0.2448[1] mas |
| Distance | 364 ± 10 ly (112 ± 3 pc) |
| Absolute magnitude (MV) | −0.38[7] |
| Details | |
| Radius | 3.2[8] R☉ |
| Luminosity | 184[9] L☉ |
| Surface gravity (log g) | 4.21[10] cgs |
| Temperature | 14,570[10] K |
| Metallicity [Fe/H] | 0.19[10] dex |
| Rotational velocity (v sin i) | 85±4[10] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Sextantis, Latinized from β Sextantis, is a variable star in the equatorial constellation of Sextans. With an apparent visual magnitude of 5.07,[2] it is faintly visible to the naked eye on a dark night. According to the Bortle scale, it can be viewed from brighter lit suburban skies. The distance to this star, based upon an annual parallax shift of 8.96 mas,[1] is around 364 light years.
This star served as a primary standard in the MK spectral classification system with a stellar classification of B6 V,[3] indicating that it is a B-type main sequence star. However, Houk and Swift (1999) list a classification of B5 IV/V, suggesting it may be transitioning into a subgiant star.[4] It has served as a uvby photometric standard, but is also categorized as an Alpha2 Canum Venaticorum variable[5] with a suspected period of 15.4 days. This lengthy a period conflicts with a relatively high projected rotational velocity of 85 km/s, leaving the explanation for the variance unresolved.[10][3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Crawford, D. L. et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal 76: 1058, doi:10.1086/111220, Bibcode: 1971AJ.....76.1058C.
- ↑ 3.0 3.1 3.2 Mathys, G. et al. (March 1986), "Photometric variability of some early-type stars", Astronomy and Astrophysics Supplement Series 63 (3): 403–416, Bibcode: 1986A&AS...63..403M.
- ↑ 4.0 4.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey (Ann Arbor, Michigan: Department of Astronomy, University of Michigan) 5, Bibcode: 1999MSS...C05....0H.
- ↑ 5.0 5.1 Kholopov, P. N. et al. (April 1989), "The 69th Name-List of Variable Stars", Information Bulletin on Variable Stars 3323 (3323): 1, Bibcode: 1989IBVS.3323....1K.
- ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ 10.0 10.1 10.2 10.3 10.4 Hempel, M.; Holweger, H. (September 2003), "Abundance analysis of late B stars. Evidence for diffusion and against weak stellar winds", Astronomy and Astrophysics 408: 1065–1076, doi:10.1051/0004-6361:20030889, Bibcode: 2003A&A...408.1065H.
- ↑ "bet Sex -- Variable Star of alpha2 CVn type", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=bet+Sex, retrieved 2016-12-13.
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