Beta Aurigae
| |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 59m 31.72293s[1] |
| Declination | +44° 56′ 50.7573″[1] |
| Apparent magnitude (V) | +1.90[2] |
| Characteristics | |
| Spectral type | A1m IV + A1m IV[3] |
| U−B color index | +0.05[2] |
| B−V color index | +0.03[2] |
| R−I color index | –0.01 |
| Variable type | Algol variable |
| Astrometry | |
| Radial velocity (Rv) | –18.2[4] km/s |
| Proper motion (μ) | RA: –56.44[1] mas/yr Dec.: –0.95[1] mas/yr |
| Parallax (π) | 40.21 ± 0.23[1] mas |
| Distance | 81.1 ± 0.5 ly (24.9 ± 0.1 pc) |
| Absolute magnitude (MV) | 0.55/0.76[5] |
| Orbit[6] | |
| Period (P) | 3.96004 days |
| Eccentricity (e) | 0.0 |
| Inclination (i) | 76.0 ± 0.4° |
| Periastron epoch (T) | 54539.0162 ± 0.0003 reduced HJD |
| Semi-amplitude (K1) (primary) | 108.053 ± 0.072 km/s |
| Semi-amplitude (K2) (secondary) | 110.911 ± 0.071 km/s |
| Details | |
| β Aur A | |
| Mass | 2.389 ± 0.013[6] M☉ |
| Radius | 2.77[7] R☉ |
| Luminosity | 48[8] L☉ |
| Surface gravity (log g) | 3.93[5] cgs |
| Temperature | 9,350[7] K |
| Rotational velocity (v sin i) | 33[7] km/s |
| Age | 570[7] Myr |
| β Aur B | |
| Mass | 2.327 ± 0.013[6] M☉ |
| Radius | 2.63[7] R☉ |
| Luminosity | 48[8] L☉ |
| Temperature | 9,200[7] K |
| Rotational velocity (v sin i) | 34[7] km/s |
| Other designations | |
Beta Aurigae (β Aurigae, abbreviated Beta Aur, β Aur), also named Menkalinan,[10] is a binary star[11] system in the northern constellation of Auriga. The combined apparent visual magnitude of the system is 1.9,[2] making it the second brightest member of the constellation after Capella. Using the parallax measurements made during the Hipparcos mission, the distance to this star system can be estimated as 81.1 light-years (24.9 parsecs), give or take a half light year margin of error.[1]
Nomenclature
Beta Aurigae is the star's Bayer designation. The traditional name Menkalinan is derived from the Arabic منكب ذي العنان mankib ðī-l-‘inān "shoulder of the rein-holder". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[12] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[13] included a table of the first two batches of names approved by the WGSN; which included Menkalinan for this star.
It is known as 五車三 (the Third Star of the Five Chariots) in traditional Chinese astronomy.
Properties
Beta Aurigae is a binary star system, although the light that the star system releases forges the appearance of a single star in the night sky. The two brightest components are metallic-lined subgiant stars belonging to the A-type stellar classification;[3] they have roughly the same mass and radius. A-type entities are hot stars that release a blue-white hued light; these two stars burn brighter and with more heat than the Sun, which is a G2-type main sequence star. The pair constitute an eclipsing spectroscopic binary; the combined apparent magnitude varies over a period of 3.96 days between +1.89 and +1.94, as every 47.5 hours one of the stars partially eclipses the other from Earth's perspective.[14]
At an angular separation of 13.9 ± 0.3 arcseconds along a position angle of 155° is a companion star that is 8.5 magnitudes fainter than the binary pair. This is a candidate member of Beta Aurigae, which would make it a triple (trinary) star system. It may be the source of the X-ray emission from the vicinity.[15] The Beta Aurigae system is believed to be a stream member of the Ursa Major Moving Group.[16]
See also
References
- 1 2 3 4 5 6 van Leeuwen, F. (November 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 - 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
- 1 2 Southworth, J.; Bruntt, H.; Buzasi, D. L. (June 2007), "Eclipsing binaries observed with the WIRE satellite. II. β Aurigae and non-linear limb darkening in light curves", Astronomy and Astrophysics, 467 (3): 1215–1226, arXiv:astro-ph/0703634, Bibcode:2007A&A...467.1215S, doi:10.1051/0004-6361:20077184.
- ↑ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Washington, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W
- 1 2 Torres, G.; Andersen, J.; Giménez, A. (February 2010), "Accurate masses and radii of normal stars: modern results and applications", The Astronomy and Astrophysics Review, 18 (1–2): 67–126, arXiv:0908.2624, Bibcode:2010A&ARv..18...67T, doi:10.1007/s00159-009-0025-1
- 1 2 3 Behr, Bradford B.; et al. (July 2011), "Stellar Astrophysics with a Dispersed Fourier Transform Spectrograph. II. Orbits of Double-lined Spectroscopic Binaries", The Astronomical Journal, 142 (1): 6, arXiv:1104.1447, Bibcode:2011AJ....142....6B, doi:10.1088/0004-6256/142/1/6
- 1 2 3 4 5 6 7 Nordstrom, B.; Johansen, K. T. (1994), "Radii and masses for beta Aurigae", Astronomy and Astrophysics, 291 (3): 777–785, Bibcode:1994A&A...291..777N
- 1 2 Kaler, James B., "MENKALINAN (Beta Aurigae)", Stars, University of Illinois, retrieved 2010-01-23
- ↑ "NLTT 8982 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-18.
- ↑ "IAU Catalog of Star Names". Retrieved 28 July 2016.
- ↑ 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.
- ↑ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
- ↑ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
- ↑ Malkov, O. Yu.; Oblak, E.; Snegireva, E. A.; Torra, J. (February 2006), "A catalogue of eclipsing variables", Astronomy and Astrophysics, 446 (2): 785–789, Bibcode:2006A&A...446..785M, doi:10.1051/0004-6361:20053137.
- ↑ De Rosa, R. J.; et al. (July 2011), "The Volume-limited A-Star (VAST) survey - I. Companions and the unexpected X-ray detection of B6-A7 stars", Monthly Notices of the Royal Astronomical Society, 415 (1): 854–866, arXiv:1103.4363, Bibcode:2011MNRAS.415..854D, doi:10.1111/j.1365-2966.2011.18765.x
- ↑ Giannuzzi, M. A. (August 1979), "On the eclipsing binaries of the Ursa Major stream", Astronomy and Astrophysics, 77 (1–2): 214–222, Bibcode:1979A&A....77..214G.