38 Aurigae

38 Aurigae
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 06h 03m 17.94729s[1]
Declination +42° 54′ 41.5433″[1]
Apparent magnitude (V) 6.08[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type K0 III[4]
B−V color index 0.979±0.004[2]
Astrometry
Radial velocity (Rv)+33.69±0.20[2] km/s
Proper motion (μ) RA: +121.023[1] mas/yr
Dec.: −144.427[1] mas/yr
Parallax (π)13.8158 ± 0.2136 mas[1]
Distance236 ± 4 ly
(72 ± 1 pc)
Absolute magnitude (MV)1.572[5]
Details
Mass1.59[5] M☉
Radius7[6] R☉
Luminosity18.47[2] L☉
Surface gravity (log g)2.95[5] cgs
Temperature4,834[5] K
Metallicity [Fe/H]−0.17[5] dex
Age3.6±1.0[7] Gyr
Other designations
38 Aur, BD+42°1473, FK5 2461, HD 40801, HIP 28677, HR 2199, SAO 40818[8]
Database references
SIMBADdata

38 Aurigae is a star located 236[1] light years away from the Sun in the northern constellation of Auriga.[8] It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 6.08.[2] The star is moving further from the Earth with a heliocentric radial velocity of +34 km/s,[2] and it has a relatively high proper motion, traversing the celestial sphere at the rate of 0.181 arc seconds per annum.[9] It is a probable member of the Hercules stream.[7]

This object is an aging giant star with a stellar classification of K0 III.[4] At the age of around 3.6[7] billion years it is a red clump giant, which indicates it is on the horizontal branch and is generating energy via helium fusion at its core.[3] The star has 1.59[5] times the mass of the Sun and has expanded to 7[6] times the Sun's radius. It is radiating 18[2] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,834 K.[5]

38 Aurigae has a faint common proper motion companion at an angular separation of 152″, which is equivalent to a projected separation of 12,160 AU. This is a red dwarf star with a class of M5.3.[10]

References

  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b Mishenina, T. V.; et al. (September 2006), "Elemental abundances in the atmosphere of clump giants", Astronomy and Astrophysics, 456 (3): 1109–1120, arXiv:astro-ph/0605615, Bibcode:2006A&A...456.1109M, doi:10.1051/0004-6361:20065141, S2CID 18764566.
  4. ^ a b Eggen, O. J. (1962), "Space-velocity vectors for 3483 stars with proper motion and radial velocity", Royal Observatory Bulletin, 51: 79, Bibcode:1962RGOB...51...79E.
  5. ^ a b c d e f g Liu, Yujuan; et al. (August 2010), "Stellar Parameters and Abundance Analysis of 58 Late G Giants", Publications of the Astronomical Society of Japan, 62 (4): 1071–1084, Bibcode:2010PASJ...62.1071L, doi:10.1093/pasj/62.4.1071.
  6. ^ a b Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
  7. ^ a b c Ramya, P.; et al. (August 2016), "Chemical compositions and kinematics of the Hercules stream", Monthly Notices of the Royal Astronomical Society, 460 (2): 1356–1370, arXiv:1604.04821, Bibcode:2016MNRAS.460.1356R, doi:10.1093/mnras/stw852.
  8. ^ a b "38 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-05-22.
  9. ^ 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, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
  10. ^ Dhital, Saurav; et al. (2010), "Sloan Low-mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs", The Astronomical Journal, 139 (6): 2566–2586, arXiv:1004.2755, Bibcode:2010AJ....139.2566D, doi:10.1088/0004-6256/139/6/2566, S2CID 661494.