79 Tauri, also known as b Tauri, is an Am star in the constellation of Taurus with an apparent magnitude of 5.0. It is a member of the Hyades open cluster and parallax measurements by Gaia give a distance of about 157 light years.
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 28m 50.1636s[1] |
| Declination | +13° 02′ 51.367″[1] |
| Apparent magnitude (V) | 5.014[2] |
| Characteristics | |
| Spectral type | kA5hF0VmF0[3] |
| U−B color index | +0.12[4] |
| B−V color index | +0.23[4] |
| Astrometry | |
| Radial velocity (Rv) | +33.7276±0.0324[5] km/s |
| Proper motion (μ) | RA: +104.066[1] mas/yr Dec.: −14.900[1] mas/yr |
| Parallax (π) | 20.7158 ± 0.0899 mas[1] |
| Distance | 157.4 ± 0.7 ly (48.3 ± 0.2 pc) |
| Absolute magnitude (MV) | 1.58[6] |
| Details | |
| Mass | 1.9[1] M☉ |
| Radius | 2.4[1] R☉ |
| Luminosity | 18[1] L☉ |
| Surface gravity (log g) | 3.88[1] cgs |
| Temperature | 7,681[1] K |
| Metallicity [Fe/H] | +0.35[6] dex |
| Rotation | 0.925 d[7] |
| Rotational velocity (v sin i) | 106.3[7] km/s |
| Age | 971[1] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of 79 Tauri shows abnormal abundances of metals, with many showing unusually strong absorption lines, but some such as calcium showing weaker lines than expected. This is represented in the spectral type kA5hF0VmF0, which is F0 based on its hydrogen lines, but A5 based on its calcium K-lines, and F0 based on the lines of other metals.[3] Other publications often give the spectral class based on hydrogen lines as A7.[8] It is classified as an Am star, a type of star with strong magnetic fields and slow rotation causing stratification of elements within its atmosphere.[9]
79 Tauri lies about two degrees south of the main V asterism of the Hyades open cluster. It lies 11 light years from the centre of the cluster and is generally considered to be a member.[10] With a mass of 1.9 M☉, it is a main sequence star with an age of 971 million years. It has an effective temperature of 7,681 K and a radius of 2.4 R☉, it radiates 18 times the luminosity of the Sun.
References
edit- ^ a b c d e f g h i j k 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.
- ^ Joner, Michael D.; Taylor, Benjamin J.; Laney, C. David; Van Wyk, Francois (2006). "Homogeneous Photometry for the Hyades: Scale-Factor and Zero-Point Tests of Previously Published BV(RI)C Photometry". The Astronomical Journal. 132 (1): 111. Bibcode:2006AJ....132..111J. doi:10.1086/504410. S2CID 122099450.
- ^ a b Islik, S. (1968). "Chemical composition and physical structure of 7 early-type stars". Memorie della Societa Astronomica Italiana. 39: 19. Bibcode:1968MmSAI..39...19I.
- ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ Leão, I. C.; Pasquini, L.; Ludwig, H. -G.; De Medeiros, J. R. (2019). "Spectroscopic and astrometric radial velocities: Hyades as a benchmark". Monthly Notices of the Royal Astronomical Society. 483 (4): 5026. arXiv:1811.08771. Bibcode:2019MNRAS.483.5026L. doi:10.1093/mnras/sty3215.
- ^ 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. S2CID 119257644.
- ^ a b van Saders, Jennifer L.; Pinsonneault, Marc H. (October 2013). "Fast Star, Slow Star; Old Star, Young Star: Subgiant Rotation as a Population and Stellar Physics Diagnostic". The Astrophysical Journal. 776 (2): 20. arXiv:1306.3701. Bibcode:2013ApJ...776...67V. doi:10.1088/0004-637X/776/2/67. S2CID 119097746. 67.
- ^ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S.
- ^ Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
- ^ Lodieu, N.; Smart, R. L.; Pérez-Garrido, A.; Silvotti, R. (2019). "A 3D view of the Hyades stellar and sub-stellar population". Astronomy and Astrophysics. 623: A35. arXiv:1901.07534. Bibcode:2019A&A...623A..35L. doi:10.1051/0004-6361/201834045. S2CID 119385406.