Beta Aurigae

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Template:Short description

β Aurigae
Template:Location mark
Location of β Aurigae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Auriga
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) Script error: No such module "val".[2] (2.602 + 2.705)[3]
Characteristics
Evolutionary stage Main sequence[4][5][6]
Spectral type A1m IV + A1m IV[7]
U−B Template:Engvar +0.05[8]
B−V Template:Engvar +0.03[8]
R−I Template:Engvar −0.01Script error: No such module "Unsubst".
Variable type Algol variable[2]
Astrometry
Radial velocity (Rv)−18.2[9] km/s
Proper motion (μ) RA: −56.44 mas/yr[1]
Dec.: −0.95 mas/yr[1]
Parallax (π)40.21±0.23 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)0.674 / 0.777[3]
Orbit[10]
Period (P)3.96004 days
Semi-major axis (a)Script error: No such module "val".[3] AU
Eccentricity (e)0.0
Inclination (i)76.0 ± 0.4°
Periastron epoch (T)54539.0162 ± 0.0003 reduced HJD
Semi-amplitude (K1)
(primary)		Script error: No such module "val". km/s
Semi-amplitude (K2)
(secondary)		Script error: No such module "val". km/s
Details
β Aur Aa
MassScript error: No such module "val".[10] Template:Solar mass
RadiusScript error: No such module "val".[7] Template:Solar radius
LuminosityScript error: No such module "val".[3] Template:Solar luminosity
Surface gravity (log g)3.93[11] cgs
Temperature8,985[3] K
Rotational velocity (v sin i)33[12] km/s
AgeScript error: No such module "val".[7] Myr
β Aur Ab
MassScript error: No such module "val".[10] Template:Solar mass
RadiusScript error: No such module "val".[7] Template:Solar radius
LuminosityScript error: No such module "val".[3] Template:Solar luminosity
Temperature8,760[3] K
Metallicity [Fe/H]{{{metal_fe2}}} dex
Rotational velocity (v sin i)34[12] km/s
AgeScript error: No such module "val".[7] Myr
Other designations
Template:Odlist[13]
Database references
SIMBADdata

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Beta Aurigae is a binary star[14] system in the northern constellation of Auriga. Its identifier is a Bayer designation that is Latinized from β Aurigae, and abbreviated Beta Aur or β Aur. This star has the official name Menkalinan, pronounced Template:IPAc-en.[15][16] The combined apparent visual magnitude of the system is 1.9,[8] 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 Script error: No such module "convert"., give or take a half-light-year margin of error.[1] It is drifting closer to the Sun with a radial velocity of −18 km/s.[9]

Along their respective orbits around the Milky Way, Beta Aurigae and the Sun are closing in on each other, so that in around one million years it will become the brightest star in the night sky.[17] It is predicted to come as close as Template:Cvt in 1.31 million years.[18]

Nomenclature

File:Astronomer Edward Charles Pickering's Harvard computers.jpg
Women computers at the Harvard College Observatory; on the wall is a graph of β Aurigae's varying brightness in December 1889.

β Aurigae is the star system'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)[19] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[20] 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

File:BetaAurLightCurve.png
A light curve for Beta Aurigae, plotted from data published by Southworth et al. (2007)[7]

Beta Aurigae is a binary star system, but it appears as a single star in the night sky. The two stars are metallic-lined stars belonging to the A-type stellar classification. Although the spectra have the luminosity class of a subgiant (IV),[7] the components are still on the main sequence stage of evolution.[4][5] This discrepancy arises from their nature as Am stars, which make them larger and more luminous than a "normal" star.[6] A-type stars are hot and release a 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.[21] The two stars are designated Aa and Ab in modern catalogues,[22][3] but have also been referred to as components 1 and 2 or A and B.[10][12]

There is an 11th magnitude optical companion with a separation of Script error: No such module "val". as of 2011, but increasing. It is also an A-class subgiant, but is an unrelated background star.[22]

At an angular separation of Script error: No such module "val". along a position angle of 155° is a companion star that is 8.5 magnitudes fainter than the primary. It may be the source of the X-ray emission from the vicinity.[23] The Beta Aurigae system is believed to be a stream member of the Ursa Major Moving Group.[24]

See also

References

  1. ↑ a b c d e Script error: No such module "citation/CS1".
  2. ↑ a b Script error: No such module "citation/CS1".
  3. ↑ a b c d e f g h Script error: No such module "citation/CS1". Menkalinan's database entry at VizieR.
  4. ↑ a b Script error: No such module "citation/CS1"..
  5. ↑ a b Script error: No such module "citation/CS1"..
  6. ↑ a b Script error: No such module "Citation/CS1".
  7. ↑ a b c d e f g Script error: No such module "citation/CS1".
  8. ↑ a b c Script error: No such module "citation/CS1".
  9. ↑ a b Script error: No such module "citation/CS1".
  10. ↑ a b c d Script error: No such module "citation/CS1".
  11. ↑ Script error: No such module "citation/CS1".
  12. ↑ a b c Script error: No such module "citation/CS1".
  13. ↑ Template:Cite simbad
  14. ↑ Script error: No such module "citation/CS1".
  15. ↑ Script error: No such module "citation/CS1".
  16. ↑ Script error: No such module "citation/CS1".
  17. ↑ Script error: No such module "citation/CS1". – based on computations from HIPPARCOS data. (The calculations exclude stars whose distance or proper motion is uncertain.) PDFScript error: No such module "Unsubst".Template:Cbignore
  18. ↑ Script error: No such module "citation/CS1".
  19. ↑ Script error: No such module "citation/CS1".
  20. ↑ Script error: No such module "citation/CS1".
  21. ↑ Script error: No such module "citation/CS1".
  22. ↑ a b Script error: No such module "citation/CS1".
  23. ↑ Script error: No such module "citation/CS1".
  24. ↑ Script error: No such module "citation/CS1".

External links

Template:Stars of Auriga

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