Beta Aurigae
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 59m 31.7s |
| Declination | +44° 56′ 51″ |
| Apparent magnitude (V) | +1.896 |
| Characteristics | |
| Spectral type | A2IV / A2IV / MV |
| U−B color index | +0.05 |
| B−V color index | +0.03 |
| R−I color index | -0.01 |
| Variable type | Algol variable |
| Astrometry | |
| Radial velocity (Rv) | −18.2 km/s |
| Proper motion (μ) | RA: −56.41 mas/yr Dec.: −0.88 mas/yr |
| Parallax (π) | 39.72 ± 0.78 mas |
| Distance | 82.1 ly (25.2 pc) |
| Absolute magnitude (MV) | 0.55/0.76[1] |
| Details | |
| Mass | 2.38/2.31[2] M☉ |
| Radius | 2.77/2.63[2] R☉ |
| Luminosity | 48/48[3] L☉ |
| Surface gravity (log g) | 3.93/3.98[1] |
| Temperature | 9,350/9,200[2] K |
| Metallicity | 100% |
| Rotation | 33/34[2] km/s |
| Age | 5.7 × 108[2] years |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
|
Beta Aurigae (β Aur, β Aurigae), traditionally named Menkalinan, is a white subgiant ternary star system approximately 85 light-years away in the constellation Auriga.
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[edit] Nomenclature
The name Menkalinan is shortened from the Arabic منكب ذي العنان mankib ðī-l-‘inān "shoulder of the rein-holder". It is known as 五車三 (the Third Star of the Five Chariots) in feudal Chinese astronomy.
[edit] System components
Beta Aurigae is actually a ternary (triple) 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, Beta Aurigae A and B, are both white subgiants falling under the A-type stellar classification; Beta Aurigae B is about the same mass and radius as A. A-type entities are hot stars that release a blue-white light; these two stars burn brighter and with more heat than the Sun, which is a G2-type subgiant star.
The third star, Beta Aurigae C, is a red dwarf star that is invisible to the naked eye. The C component is about 330 AU from the AB pair.
[edit] Variability
Beta Aurigae's primary and secondary stars constitute an eclipsing spectroscopic binary; the combined apparent magnitude varies over a period of 3.96004 days between +1.85 and +1.93, as every 47.5 hours one of the stars partially eclipses the other from Earth's perspective.
Beta Aurigae is believed to be a stream star member of the Ursa Major Moving Group.
[edit] See also
[edit] References
- ^ a b 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. Bibcode 2010A&ARv..18...67T. doi:10.1007/s00159-009-0025-1.
- ^ a b c d e Nordstrom, B.; Johansen, K. T.. "Radii and masses for beta Aurigae". Astronomy and Astrophysics 291 (3): 777–785. Bibcode 1994A&A...291..777N.
- ^ Kaler, James B.. "MENKALINAN (Beta Aurigae)". University of Illinois. http://stars.astro.illinois.edu/sow/menkalinan.html. Retrieved 2010-01-23.
[edit] External links
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