Tau Aurigae
(Redirected from HR 1995)
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 49m 10.43826s[1] |
| Declination | +39° 10′ 51.8627″[1] |
| Apparent magnitude (V) | 4.505[2] |
| Characteristics | |
| Spectral type | G8 III[3] |
| U−B color index | +0.692[2] |
| B−V color index | +0.956[2] |
| R−I color index | 0.49 |
| Astrometry | |
| Radial velocity (Rv) | –19.32 ± 0.19[4] km/s |
| Proper motion (μ) | RA: –28.30[1] mas/yr Dec.: –24.97[1] mas/yr |
| Parallax (π) | 15.5940 ± 0.2061 mas[5] |
| Distance | 209 ± 3 ly (64.1 ± 0.8 pc) |
| Absolute magnitude (MV) | 0.50[6] |
| Details | |
| Mass | 2.55[7] M☉ |
| Radius | 11[4] R☉ |
| Luminosity | 63[4] L☉ |
| Surface gravity (log g) | 2.7[4] cgs |
| Temperature | 4,887[4] K |
| Metallicity [Fe/H] | –0.27[4] dex |
| Rotational velocity (v sin i) | 3.8[4] km/s |
| Age | 660 - 890[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Tau Aurigae, Latinized from τ Aurigae, is a star in the northern constellation Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.505,[2] and is approximately 207 light-years (63 parsecs) distant from Earth.
Tau Aurigae is an evolved giant star with a stellar classification of G8 III.[3] It has expanded to 11 times the radius of the Sun and shines with 63 times the Sun's luminosity. This energy is radiated into outer space from the outer atmosphere at an effective temperature of 4,887.[4] This heat gives it the yellow-hued glow of a G-type star.[9]
References
[edit]- ^ a b c d 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.
- ^ a b c d Oja, T. (August 1986), "UBV photometry of stars whose positions are accurately known. III", Astronomy and Astrophysics Supplement Series, 65 (2): 405–409, Bibcode:1986A&AS...65..405O.
- ^ a b Roman, Nancy G. (July 1952), "The Spectra of the Bright Stars of Types F5-K5", Astrophysical Journal, 116: 122, Bibcode:1952ApJ...116..122R, doi:10.1086/145598.
- ^ a b c d e f g h 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, S2CID 121883397.
- ^ 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.
- ^ 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 Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Girardi, Léo; MacDonald, Nick; Majewski, Steven R.; Nidever, David L. (2016). "Determining Ages of APOGEE Giants with Known Distances". The Astrophysical Journal. 817 (1): 40. arXiv:1511.04088. Bibcode:2016ApJ...817...40F. doi:10.3847/0004-637x/817/1/40. S2CID 118675933.
- ^ "tau Aur -- Star in double system", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-08-20.
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2013-12-03, retrieved 2012-01-16.
