Pi Aurigae, Latinized from π Aurigae, is the Bayer designation for a single,[11] red-hued star in the northern constellation of Auriga. Located about one degree north of the 2nd magnitude star Beta Aurigae,[12] Pi Aurigae is visible to the naked eye with an apparent visual magnitude of 4.25[2] Based upon parallax measurements, it is approximately 720 light-years (220 parsecs) away from Earth.[1] At that distance, the brightness of the star is diminished by 0.54 in magnitude from extinction caused by interstellar gas and dust.[6]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 59m 56.09792s[1] |
| Declination | +45° 56′ 12.2457″[1] |
| Apparent magnitude (V) | 4.25[2] |
| Characteristics | |
| Evolutionary stage | asymptotic giant branch[3] |
| Spectral type | M3 II[4] |
| U−B color index | +1.83[2] |
| B−V color index | +1.72[2] |
| Variable type | LC[5] |
| Astrometry | |
| Radial velocity (Rv) | 0.71±0.76[6] km/s |
| Proper motion (μ) | RA: −3.755 mas/yr[1] Dec.: −7.785 mas/yr[1] |
| Parallax (π) | 4.515 ± 0.241 mas[1] |
| Distance | 720 ± 40 ly (220 ± 10 pc) |
| Absolute magnitude (MV) | −2.46[7] |
| Details | |
| Radius | 218.6[8] R☉ |
| Luminosity | 6,630±1,054[8] L☉ |
| Surface gravity (log g) | 0.55±0.10[9] cgs |
| Temperature | 3,525±125[8] K |
| Metallicity [Fe/H] | 0.03±0.04[9] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi Aurigae is an evolved bright giant star with a stellar classification of M3 II.[4] After exhausting the supply of hydrogen at its core the star has expanded to approximately 219 times the size of the Sun.[8] It is classified as a slow irregular variable of type LC and its brightness varies from magnitude +4.24 to +4.34.[5] On average, the star is radiating 6,630 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,525 K.[8]
References
edit- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d 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.
- ^ Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal, 104 (1): 275–313, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
- ^ a b Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11 (1): 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333.
- ^ a b Ruban, E. V.; et al. (September 2006), "Spectrophotometric observations of variable stars", Astronomy Letters, 32 (9): 604–607, Bibcode:2006AstL...32..604R, doi:10.1134/S1063773706090052, S2CID 121747360.
- ^ a b 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.
- ^ 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.
- ^ a b c d e McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society, 471 (1): 770–791, arXiv:1706.02208, doi:10.1093/mnras/stx1433, ISSN 0035-8711 Pi Aurigae's database entry at VizieR.
- ^ a b Wu, Yue; et al. (January 2011), "Coudé-feed stellar spectral library - atmospheric parameters", Astronomy and Astrophysics, 525: A71, arXiv:1009.1491, Bibcode:2011A&A...525A..71W, doi:10.1051/0004-6361/201015014, S2CID 53480665.
- ^ "pi. Aur -- Pulsating variable Star", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-08-20.
- ^ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ O'Meara, Stephen James (2007), Steve O'Meara's Herschel 400 Observing Guide, Cambridge University Press, p. 23, ISBN 978-0521858939.