Astronomy:Lambda Aurigae

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Short description: Solar analog star in the constellation Auriga
λ Aurigae
Auriga constellation map.svg
Red circle.svg
Location of λ Aurigae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Auriga
Right ascension  05h 19m 08.47546s[1]
Declination +40° 05′ 56.5896″[1]
Apparent magnitude (V) 4.71[2]
Characteristics
Spectral type G1 V[3] or G1.5 IV-V Fe-1[4]
U−B color index +0.13[2]
B−V color index +0.62[2]
R−I color index 0.32
Astrometry
Radial velocity (Rv)+66.53±0.14[1] km/s
Proper motion (μ) RA: +520.581[1] mas/yr
Dec.: −664.826[1] mas/yr
Parallax (π)80.1054 ± 0.2158[1] mas
Distance40.7 ± 0.1 ly
(12.48 ± 0.03 pc)
Absolute magnitude (MV)4.20[5]
Details
Mass1.081+0.054
−0.029
[6] M
Radius1.331±0.021[3] R
Luminosity1.732±0.022[3] L
Surface gravity (log g)4.02[7] cgs
Temperature5,890±4.3[8] K
Metallicity [Fe/H]+0.12[9] dex
Rotational velocity (v sin i)2[10] km/s
Age4,[9] 5.0–7.9[11] Gyr
Other designations
λ Aur, 15 Aurigae, BD+39° 1248, FK5 1145, GJ 197, HD 34411, HIP 24813, HR 1729, SAO 40233, LFT 403, LHS 1753, LTT 11625[12]
Database references
SIMBADdata
ARICNSdata

Lambda Aurigae, Latinized from λ Aurigae, is the Bayer designation for a solar analog[9] star in the northern constellation of Auriga.[13] It is visible to the naked eye with an apparent visual magnitude of 4.71.[2] Based upon parallax measurements, it is approximately 40.7 light-years (12.5 parsecs) distant from the Earth.[14] The star is drifting further away with a high radial velocity of +66.5 km/s,[1] having come to within 24.4 ly (7.5 pc) some 117,300 years ago.[15] It has a high proper motion, traversing the celestial sphere at the rate of 0.844 per year.[16]

Properties

This is a G-type main sequence star with a stellar classification of G1 V.[3] It is sometimes listed with a class of G1.5 IV-V Fe-1,[4] which indicates the spectrum is showing some features of a more evolved subgiant star along with a noticeable underabundance of iron. In terms of composition it is similar to the Sun, while the mass and radius are slightly larger.[6] It is 73% more luminous than the Sun[3] and radiates this energy from its outer atmosphere at an effective temperature of 5890 K.[8] At this heat, the star glows with the yellow hue of a G-type star.[17] It has a low level of surface activity and is a candidate Maunder minimum analog.[18]

Lambda Aurigae has been examined for the presence of excess infrared emission that may indicate the presence of a circumstellar disk of dust, but no significant surplus has been observed.[9] It is a possible member of the Epsilon Indi Moving Group of stars that share a common motion through space. The space velocity components of this star are [U, V, W] = [+76, –39, –6] km/s.[19]

Name

This star may have been called by the name Al Hurr, meaning the fawn in Arabic.[20] Lambda Aurigae, along with μ Aur and σ Aur, were Kazwini's Al Ḣibāʽ (ألحباع), the Tent.[20] 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.[21]

In Chinese, 咸池 (Xián Chí), meaning Pool of Harmony, refers to an asterism consisting of λ Aurigae, ρ Aurigae and HD 36041.[22] Consequently, the Chinese name for λ Aurigae itself is 咸池三 (Xián Chí sān, English: the Third Star of Pool of Harmony.)[23]

Observation

From Earth, Lambda Aurigae has an apparent magnitude of 4.71. The closest large neighboring star to Lambda Aurigae is Capella, located 4.5 light-years (1.4 parsecs) away.[24] Hypothetically viewed from Lambda Aurigae, Capella's quadruple star system would have an apparent magnitude of approximately -5.48,[25] about 40 times brighter than Sirius can be seen at maximum brightness from Earth.[26]

References

  1. Jump up to: 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.
  2. Jump up to: 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. Jump up to: 3.0 3.1 3.2 3.3 3.4 Boyajian, Tabetha S. et al. (February 2012), "Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars", The Astrophysical Journal 746 (1): 101, doi:10.1088/0004-637X/746/1/101, Bibcode2012ApJ...746..101B. . See Table 10.
  4. Jump up to: 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  5. Holmberg, J. et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, doi:10.1051/0004-6361/200811191, Bibcode2009A&A...501..941H. 
  6. Jump up to: 6.0 6.1 Takeda, Genya et al. (February 2007), "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series 168 (2): 297–318, doi:10.1086/509763, Bibcode2007ApJS..168..297T. 
  7. Chen, Y. Q. et al. (February 2000), "Chemical composition of 90 F and G disk dwarfs", Astronomy and Astrophysics Supplement 141 (3): 491–506, doi:10.1051/aas:2000124, Bibcode2000A&AS..141..491C. 
  8. Jump up to: 8.0 8.1 Kovtyukh, V. V. et al. (2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics 411 (3): 559–564, doi:10.1051/0004-6361:20031378, Bibcode2003A&A...411..559K. 
  9. Jump up to: 9.0 9.1 9.2 9.3 Greaves, J. S.; Wyatt, M. C.; Bryden, G. (August 2009), "Debris discs around nearby solar analogues", Monthly Notices of the Royal Astronomical Society 397 (2): 757–762, doi:10.1111/j.1365-2966.2009.15048.x, Bibcode2009MNRAS.397..757G. 
  10. Takeda, Yoichi et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan 57 (1): 13–25, doi:10.1093/pasj/57.1.13, Bibcode2005PASJ...57...13T. 
  11. Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal 687 (2): 1264–1293, doi:10.1086/591785, Bibcode2008ApJ...687.1264M. 
  12. "lam Aur". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Aur. 
  13. Kaler, James, "LAMBDA AUR (Lambda Aurigae)", Stars, http://stars.astro.illinois.edu/sow/lambdaaur.html, retrieved 2011-12-11. 
  14. van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V.  Note: see VizieR catalogue I/311.
  15. Bailer-Jones, C.A.L. et al. (2018), "New stellar encounters discovered in the second Gaia data release", Astronomy & Astrophysics 616: A37, doi:10.1051/0004-6361/201833456, Bibcode2018A&A...616A..37B. 
  16. Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode2005AJ....129.1483L. 
  17. "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on March 18, 2012, https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16. 
  18. Lubin, Dan; Tytler, David; Kirkman, David (March 2012), "Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations", The Astrophysical Journal Letters 747 (2): L32, doi:10.1088/2041-8205/747/2/L32, Bibcode2012ApJ...747L..32L. 
  19. Kovacs, N.; Foy, R. (August 1978), "A detailed analysis of three stars in the Eggen's Epsilon INDI moving group", Astronomy and Astrophysics 68 (1–2): 27–31, Bibcode1978A&A....68...27K. 
  20. Jump up to: 20.0 20.1 Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 91. ISBN 978-0-486-21079-7. https://archive.org/details/starnamestheirlo00alle/page/91. Retrieved 2010-12-12. 
  21. Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, California Institute of Technology: Jet Propulsion Laboratory, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005197_1972005197.pdf, retrieved 2012-08-19. 
  22. (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.
  23. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 13 日
  24. "Capella 4". SolStation. http://www.solstation.com/stars2/capella4.htm. 
  25. "Combined apparent magnitude of 2 stars". WolframΑlpha. https://www.wolframalpha.com/widgets/view.jsp?id=aa35819112b597d719cc24ba31e63c34. 
  26. "Magnitude Arithmetic". Weekly Topic. Caglow. http://www.caglow.com/info/wtopic/mag-arith. 

External links