Astronomy:AR Aurigae

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Short description: Binary star system in the constellation Auriga
AR Aurigae
ARAurLightCurve.png
A visual band light curve for AR Aurigae, adapted from Johansen (1970)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Auriga
Right ascension  05h 18m 18.896s[2]
Declination +33° 46′ 02.52″[2]
Apparent magnitude (V) 6.144[3]
Characteristics
Spectral type B9V + B9.5V[4]
U−B color index −0.18[5]
B−V color index −0.06[5]
Variable type Algol[6]
Astrometry
Radial velocity (Rv)25.4±0.9[7] km/s
Proper motion (μ) RA: +15.254[2] mas/yr
Dec.: −29.225[2] mas/yr
Parallax (π)7.0735 ± 0.0461[2] mas
Distance461 ± 3 ly
(141.4 ± 0.9 pc)
Absolute magnitude (MV)1.11/1.17[8]
Details
AR Aur A
Mass2.552±0.008[4] M
Radius1.781[9] R
Luminosity41[8] L
Surface gravity (log g)4.33[4] cgs
Temperature10,950±150[4] K
Rotational velocity (v sin i)10[9] km/s
AR Aur B
Mass2.367±0.008[4] M
Radius1.816[9] R
Luminosity34[8] L
Surface gravity (log g)4.28[4] cgs
Temperature10,350±150[4] K
Rotational velocity (v sin i)11[9] km/s
Other designations
Database references
SIMBADdata

AR Aurigae (AR Aur), also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.[10]

Both components are blue-white B-type main-sequence stars that do not fill their Roche lobes. The system has a mean apparent magnitude of +6.15. However, the orbit of the stars are oriented in such a way that they periodically eclipse each other, so AR Aurigae is a variable star and its brightness varies from magnitude +6.15 to +6.82 with a period of 4.13 days.[6]

The primary component of AR Aurigae is known to be a mercury-manganese star, also known as an HgMn star. As the name implies, these stars have over-abundances of the elements mercury and manganese, and also often xenon and other elements.[4] Because AR Aurigae is an eclipsing binary (in fact, it is the only known eclipsing binary with a mercury-manganese star), accurate characterization of its parameters has been made possible. Based on the light-time effect observed from the stars, it is inferred that there is a third star with a mass of 0.54 M, orbiting at a separation of 13 au every 23.7 years.[4]

References

  1. Johansen, K. T. (January 1970). "Light curve and photometric elements of AR Aurigae". Astronomy & Astrophysics 4: 1–10. Bibcode1970A&A.....4....1J. 
  2. 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Folsom, C. P.; Kochukhov, O.; Wade, G. A.; Silvester, J.; Bagnulo, S. (2010). "Magnetic field, chemical composition and line profile variability of the peculiar eclipsing binary star AR Aur★". Monthly Notices of the Royal Astronomical Society 407 (4): 2383. doi:10.1111/j.1365-2966.2010.17057.x. Bibcode2010MNRAS.407.2383F. 
  5. 5.0 5.1 Nicolet, B. (1978). "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System". Astronomy and Astrophysics Supplement Series 34: 1–49. Bibcode1978A&AS...34....1N. 
  6. 6.0 6.1 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode2009yCat....102025S. 
  7. Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode1953GCRV..C......0W. 
  8. 8.0 8.1 8.2 Nordstrom, B.; Johansen, K. T. (1994). "Radii and masses for the young star AR Aurigae". Astronomy and Astrophysics 282: 787. Bibcode1994A&A...282..787N. 
  9. 9.0 9.1 9.2 9.3 Eker, Z.; Bilir, S.; Soydugan, F.; Gökçe, E. Yaz; Soydugan, E.; Tüysüz, M.; Şenyüz, T.; Demircan, O. (2014). "The Catalogue of Stellar Parameters from the Detached Double-Lined Eclipsing Binaries in the Milky Way". Publications of the Astronomical Society of Australia 31. doi:10.1017/pasa.2014.17. Bibcode2014PASA...31...24E. 
  10. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry

External links