Lambda Aurigae

Lambda Aurigae (λ Aur, 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 made during the Hipparcos mission, it is approximately 41.2 light-years (12.6 parsecs) distant from the Earth.[1]

λ Aurigae
Location of λ Aurigae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension  05h 19m 08.47420s[1]
Declination +40° 05′ 56.5826″[1]
Apparent magnitude (V) 4.71[2]
Characteristics
Spectral type G1 V[3]
U−B color index +0.13[2]
B−V color index +0.62[2]
R−I color index 0.32
Astrometry
Radial velocity (Rv)66.5[4] km/s
Proper motion (μ) RA: +518.99±0.26[1] mas/yr
Dec.: −665.06±0.13[1] mas/yr
Parallax (π)79.17 ± 0.28[1] mas
Distance41.2 ± 0.1 ly
(12.63 ± 0.04 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
Temperature5890±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
15 Aurigae, BD+39° 1248, FK5 1145, GJ 197, HD 34411, HIP 24813, HR 1729, LFT 403, LHS 1753, LTT 11625, SAO 40233.[12]
Database references
SIMBADdata
ARICNSdata

Description

This is a G-type main sequence star with a stellar classification of G1 V.[3] 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.[14] It has a low level of surface activity and is a candidate Maunder minimum analog.[15]

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.[16]

Name

This star may have been called by the name Al Hurr, meaning the fawn in Arabic.[17] Lambda Aurigae, along with μ Aur and ρ Aur, were Kazwini's Al Ḣibāʽ (ألحباع), the Tent.[17] 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.[18]

In Chinese, 咸池 (Xián Chí), meaning Pool of Harmony, refers to an asterism consisting of λ Aurigae, ρ Aurigae and HD 36041.[19] Consequently, the Chinese name for λ Aurigae itself is 咸池三 (Xián Chí sān, English: the Third Star of Pool of Harmony.)[20]

References
  1. van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311.
  2. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  3. 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, arXiv:1112.3316, Bibcode:2012ApJ...746..101B, doi:10.1088/0004-637X/746/1/101.. See Table 10.
  4. Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics, 418 (3): 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959.
  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, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  6. 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, arXiv:astro-ph/0607235, Bibcode:2007ApJS..168..297T, doi:10.1086/509763.
  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, arXiv:astro-ph/9912342, Bibcode:2000A&AS..141..491C, doi:10.1051/aas:2000124.
  8. 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, arXiv:astro-ph/0308429, Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378.
  9. 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, arXiv:0907.3677, Bibcode:2009MNRAS.397..757G, doi:10.1111/j.1365-2966.2009.15048.x.
  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, Bibcode:2005PASJ...57...13T, doi:10.1093/pasj/57.1.13.
  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, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785.
  12. "lam Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-19.
  13. Kaler, James, "LAMBDA AUR (Lambda Aurigae)", Stars, retrieved 2011-12-11.
  14. "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 10, 2012, retrieved 2012-01-16.
  15. 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, Bibcode:2012ApJ...747L..32L, doi:10.1088/2041-8205/747/2/L32.
  16. 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, Bibcode:1978A&A....68...27K.
  17. 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. Retrieved 2010-12-12.
  18. Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), California Institute of Technology: Jet Propulsion Laboratory, retrieved 2012-08-19.
  19. (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.
  20. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 13 日
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