1 Aurigae

1 Aurigae

Location of 1 Aurigae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Perseus
Right ascension	04^h 49^m 54.63946^s[1]
Declination	37° 29′ 17.7936″[1]
Apparent magnitude (V)	4.89[2]
Characteristics
Spectral type	K3.5IIIBa0.2:[3]
U−B color index	+1.71[4]
B−V color index	+1.45[4]
Astrometry
Radial velocity (Rv)	−24.65[5] km/s
Proper motion (μ)	RA: −36.89[1] mas/yr Dec.: +38.85[1] mas/yr
Parallax (π)	6.48 ± 0.44 mas[1]
Distance	500 ± 30 ly (150 ± 10 pc)
Absolute magnitude (MV)	−1.04[2]
Details
Mass	1.49[6] M☉
Radius	44±5[7] R☉
Luminosity	561[2] L☉
Surface gravity (log g)	1.12[8] cgs
Temperature	4,102[8] K
Metallicity [Fe/H]	−0.30[8] dex
Rotational velocity (v sin i)	1.6[9] km/s
Age	3.93[6] Gyr
Other designations
1 Aur, BD+37°969, FK5 1133, GC 5868, HD 30504, HIP 22453, HR 1533, SAO 57447[10]
Database references
SIMBAD	data

1 Aurigae is the original name for a star now in the constellation Perseus. It was the first entry in John Flamsteed's catalogue of stars in Auriga. When Eugène Joseph Delporte drew up simplified boundaries for the constellations on behalf of the International Astronomical Union in 1930, 1 Aurigae ended up over the border in Perseus. To avoid confusion, the star may instead be referred to by its Harvard Revised catalogue number, HR 1533.

Based upon its parallax measurement of 6.48 mas, this star is located approximately 520 light years from Earth.^[1] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.89.^[2] 1 Aurigae is moving closer to the Earth with a heliocentric radial velocity of −25 km/s.^[5]

This is a possible binary star^[11] system, based upon the status of the visible component as a mild barium star.^[12] The primary is an aging giant star with a stellar classification of K3.5 III Ba0.2:.^[3] It is 3.9^[6] billion years old with 1.49^[6] times the mass of the Sun and around 44^[7] times the Sun's radius. This star is radiating 561^[2] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,102 K.^[8] The suspected companion star should be a white dwarf that previously transferred s-process elements to the visible member.^[12]

References

1. Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
2. 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. Vizier catalog entry
3. Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
4. Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally Published in: Institut d'Astronomie. 2168. Bibcode:2006yCat.2168....0M.Vizier catalog entry
5. Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data". Astronomy & Astrophysics. 430: 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
6. Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
7. van Belle, G. T.; et al. (2009). "Supergiant temperatures and linear radii from near-infrared interferometry". Monthly Notices of the Royal Astronomical Society. 394 (4): 1925. arXiv:0811.4239. Bibcode:2009MNRAS.394.1925V. doi:10.1111/j.1365-2966.2008.14146.x. S2CID 118372600.
8. Earle Luck, R. (2014). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137.
9. De Medeiros, J. R.; Mayor, M. (1999). "A catalog of rotational and radial velocities for evolved stars". Astronomy and Astrophysics Supplement Series. 139 (3): 433. arXiv:astro-ph/0608248. Bibcode:1999A&AS..139..433D. doi:10.1051/aas:1999401. Vizier catalog entry
10. "1 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-30.
11. 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.
12. Escorza, A.; et al. (December 2017). "Hertzsprung-Russell diagram and mass distribution of barium stars". Astronomy & Astrophysics. 608: 13. arXiv:1710.02029. Bibcode:2017A&A...608A.100E. doi:10.1051/0004-6361/201731832. S2CID 119428276. A100.