Upsilon Aurigae
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga[1] |
| Right ascension | 05h 51m 02.437s[2] |
| Declination | +37° 18′ 20.05″[2] |
| Apparent magnitude (V) | 4.74[3] |
| Characteristics | |
| Evolutionary stage | Asymptotic giant branch[4] |
| Spectral type | M0 III[5] |
| U−B color index | +1.93[3] |
| B−V color index | +1.62[3] |
| R−I color index | 1.07[citation needed] |
| Variable type | Suspected[6] |
| Astrometry | |
| Radial velocity (Rv) | +37.62±0.34[7] km/s |
| Proper motion (μ) | RA: +36.426 mas/yr[2] Dec.: −45.606 mas/yr[2] |
| Parallax (π) | 5.7358±0.2055 mas[2] |
| Distance | 570 ± 20 ly (174 ± 6 pc) |
| Absolute magnitude (MV) | −1.28[1] |
| Details[8] | |
| Mass | 1.64±0.22 M☉ |
| Radius | 74.2+8.7 −7.0 R☉ |
| Luminosity | 1,165±250 L☉ |
| Surface gravity (log g) | 1.16+0.04 −0.08[9] cgs |
| Temperature | 3,912±52 K |
| Age | 1.98±0.68 Gyr |
| Other designations | |
| υ Aur, 31 Aurigae, NSV 2661, BD+37 1336, FK5 2440, GC 7322, HD 38944, HIP 27639, HR 2011, SAO 58496, PPM 70915[10] | |
| Database references | |
| SIMBAD | data |
Upsilon Aurigae is a single[11] star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinised from υ Aurigae, and abbreviated Upsilon Aur or υ Aur. This star has an apparent visual magnitude of 4.74,[3] which means it is bright enough to be seen with the naked eye. Based upon parallax measurements, this star is approximately 570 light-years (170 parsecs) distant from the Earth. It is drifting further away with a radial velocity of +37 km/s.[7]
This is an evolved red giant star with a stellar classification of M0 III.[5] It is a suspected variable star[6] and is currently on the asymptotic giant branch, which means it is generating energy through the fusion of helium along a shell surrounding a small, inert core of carbon and oxygen.[4] The star is two billion years old with 1.64 times the mass of the Sun and has expanded to 61 times the Sun's radius. It is radiating 1,165 times the Sun's luminosity from its photosphere at an effective temperature of 3,912 K.[8]
References
[edit]- ^ a b 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. XHIP record for this object at VizieR.
- ^ a b c d 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
- ^ a b 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 Keenan, Philip C.; Barnbaum, Cecilia (June 1999), "Revision and Calibration of MK Luminosity Classes for Cool Giants by HIPPARCOS Parallaxes", The Astrophysical Journal, 518 (2): 859–865, Bibcode:1999ApJ...518..859K, doi:10.1086/307311, S2CID 121902473.
- ^ a b Hamada, K.; et al. (January 1979), "On the Variability of upsilon Aurigae", Information Bulletin on Variable Stars, 1531: 1, Bibcode:1979IBVS.1531....1H.
- ^ a b Famaey, B.; et al. (May 2009), "Spectroscopic binaries among Hipparcos M giants. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv:0901.0934, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698.
- ^ a b Baines, E.; et al. (2017), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1): 30, arXiv:1712.08109, Bibcode:2018AJ....155...30B, doi:10.3847/1538-3881/aa9d8b, S2CID 119427037.
- ^ Takagi, Yuhei; et al. (June 2011), "Age Determinations of Early-M Type Pre-Main Sequence Stars Using a High-Resolution Near-Infrared Spectroscopic Method", Publications of the Astronomical Society of Japan, 63 (3): 677–684, Bibcode:2011PASJ...63..677T, doi:10.1093/pasj/63.3.677.
- ^ "* ups Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-23.
- ^ 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.
