Astronomy:Mu Aurigae

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Short description: Star in the constellation Auriga
Mu Aurigae
Auriga constellation map.svg
Red circle.svg
Location of μ Aurigae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Auriga
Right ascension  05h 13m 25.71733s[1]
Declination +38° 29′ 04.1879″[1]
Apparent magnitude (V) +4.88[2]
Characteristics
Spectral type A4 Vm[3][4] (kA3hA8VmA8[5])
U−B color index +0.10[2]
B−V color index +0.18[2]
Astrometry
Radial velocity (Rv)+26.0±1.2[6] km/s
Proper motion (μ) RA: −19.545[7] mas/yr
Dec.: −72.456[7] mas/yr
Parallax (π)20.7218 ± 0.4971[7] mas
Distance157 ± 4 ly
(48 ± 1 pc)
Absolute magnitude (MV)+1.47[8]
Details
Mass2.09[9] M
Radius3.15[7] R
Luminosity22.95[7] L
Surface gravity (log g)3.4[10] cgs
Temperature7,500[10] K
Metallicity [Fe/H]−0.3[10] dex
Rotational velocity (v sin i)80.0[10] km/s
Age560[9] Myr
Other designations
μ Aur, 11 Aurigae, BD+38°1063, FK5 192, HD 33641, HIP 24340, HR 1689, SAO 57755, WDS J05134+3829AB[11]
Database references
SIMBADdata

Mu Aurigae, Latinized as μ Aurigae, is the Bayer designation for an unconfirmed binary star[12] in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of +4.88.[2] Based upon an annual parallax shift of 20.7218±0.4971 mas as seen from Earth,[7] is located 157 light-years from the Sun.

This is an A-type main-sequence star with a stellar classification of A4 Vm;[4] the 'm' suffix indicating that abnormal abundances of heavier elements appear in the star's spectrum, making this an Am star. It is 560[9] million years old with a projected rotational velocity of 80 km/s.[10] It has double[9] the mass of the Sun and is radiating 23[7] times the Sun's luminosity at an effective temperature of 7,500 K.[10]

A very close companion has been reported using speckle interferometry,[12] but this remains unconfirmed. The separation at discovery in 1986 was 0.07 mas and it was measured at 0.066 mas in 1999. It was catalogued by Hipparcos as a problem binary, indicating that the measurements of its position were not consistent with the motion of a single star, but no satisfactory orbit could be found to match the motion[12]

Name

This star, along with λ Aur and σ Aur, were Kazwini's Al Ḣibāʽ (ألحباع), the Tent.[13] According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Ḣibāʽ were the title for three stars: λ Aur as Al Ḣibāʽ I, μ Aur as Al Ḣibāʽ II and σ Aur as Al Ḣibāʽ III.[14]

In Chinese, 天潢 (Tiān Guāng), meaning Celestial Pier, refers to an asterism consisting of μ Aurigae, 19 Aurigae, φ Aurigae, 14 Aurigae and σ Aurigae.[15] Consequently, μ Aurigae itself is known as 天潢五 (Tiān Guāng wu, English: the First Star of Celestial Pier).[16]

References

  1. 1.0 1.1 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. 
  2. 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode2002A&A...393..897R. 
  4. 4.0 4.1 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  5. Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", The Astrophysical Journal Supplement Series 99: 135, doi:10.1086/192182, Bibcode1995ApJS...99..135A. 
  6. 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, Bibcode2012A&A...546A..61D. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 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. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  8. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  9. 9.0 9.1 9.2 9.3 De Rosa, R. J. et al. (January 2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society 437 (2): 1216–1240, doi:10.1093/mnras/stt1932, Bibcode2014MNRAS.437.1216D. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 Gebran, M.; Farah, W.; Paletou, F.; Monier, R.; Watson, V. (2016), "A new method for the inversion of atmospheric parameters of A/Am stars", Astronomy and Astrophysics 589: A83, doi:10.1051/0004-6361/201528052, Bibcode2016A&A...589A..83G. 
  11. "mu Aur". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=mu+Aur. 
  12. 12.0 12.1 12.2 Mason, Brian D.; Martin, Christian; Hartkopf, William I.; Barry, Donald J.; Germain, Marvin E.; Douglass, Geoffrey G.; Worley, Charles E.; Wycoff, Gary L. et al. (1999), "Speckle Interferometry of New and Problem HIPPARCOS Binaries", The Astronomical Journal 117 (4): 1890, doi:10.1086/300823, Bibcode1999AJ....117.1890M. 
  13. Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 91, ISBN 0-486-21079-0, https://archive.org/details/starnamestheirlo00alle/page/91, retrieved 2010-12-12. 
  14. Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005197_1972005197.pdf. 
  15. (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN:978-986-7332-25-7.
  16. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 13 日

External links