Phi Aurigae

φ Aurigae
Location of φ Aurigae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 05h 27m 38.88417s[1]
Declination +34° 28′ 33.1639″[1]
Apparent magnitude (V) 5.089[2]
Characteristics
Spectral type K3 IIIp[3]
U−B color index +1.649[2]
B−V color index +1.411[2]
R−I color index 0.47
Astrometry
Radial velocity (Rv)+30.78[4] km/s
Proper motion (μ) RA: –1.324[1] mas/yr
Dec.: –38.746[1] mas/yr
Parallax (π)6.7629 ± 0.1659 mas[1]
Distance480 ± 10 ly
(148 ± 4 pc)
Absolute magnitude (MV)−0.62[5]
Details
Radius33.97±1.05[6] R☉
Luminosity307±15[6] L☉
Surface gravity (log g)1.75[3] cgs
Temperature4,222[6] K
Metallicity [Fe/H]–0.03[3] dex
Rotational velocity (v sin i)1.6[7] km/s
Other designations
φ Aur, 24 Aurigae, BD+34 1048, HD 35620, HIP 25541, HR 1805, SAO 58051.[8]
Database references
SIMBADdata
φ Aurigae in optical light

Phi Aurigae, Latinized from φ Aurigae, is a giant star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 5.089.[2] It lies 10′ from another faint naked-eye star HD 35520, between the three open clusters M36 and M38, and NGC 1893.

The distance to this star, as determined from parallax measurements, is approximately 480 light-years (150 parsecs) with a 10 light-year margin of error.[9] This is an evolved giant star with a stellar classification of K3 IIIp[3] and an estimated radius equal to 34 times the radius of the Sun. The outer envelope has an effective temperature of 4,222 K,[6] giving it the cool orange-hued glow of a K-type star.

References

  1. ^ a b c d e 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 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants.", Monthly Notices of the Royal Astronomical Society, 172 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
  3. ^ a b c d Cenarro, A. J.; et al. (January 2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society, 374 (2): 664–690, arXiv:astro-ph/0611618, Bibcode:2007MNRAS.374..664C, doi:10.1111/j.1365-2966.2006.11196.x, S2CID 119428437.
  4. ^ Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
  5. ^ 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.
  6. ^ a b c d van Belle, Gerard T.; von Braun, Kaspar; Ciardi, David R.; Pilyavsky, Genady; Buckingham, Ryan S.; Boden, Andrew F.; Clark, Catherine A.; Hartman, Zachary; van Belle, Gerald; Bucknew, William; Cole, Gary (2021-12-01). "Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration against Spectral Types and V - K Color". The Astrophysical Journal. 922 (2): 163. arXiv:2107.09205. Bibcode:2021ApJ...922..163V. doi:10.3847/1538-4357/ac1687. ISSN 0004-637X. Phi Aurigae's database entry at VizieR.
  7. ^ De Medeiros, J. R.; et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics, 363: 239–243, arXiv:astro-ph/0010273, Bibcode:2000A&A...363..239D.
  8. ^ "* phi Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-23.
  9. ^ 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, S2CID 18759600. Note: see VizieR catalogue I/311.