71 Tauri


71 Tauri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Taurus
Right ascension 04h 26m 20.77302s[1]
Declination +15° 37′ 05.7885″[1]
Apparent magnitude (V) +4.48[2]
Spectral type F0 V[3]
U−B color index +0.13[2]
B−V color index +0.25[2]
Variable type δ Sct[4]
Radial velocity (Rv)+38.3[5] km/s
Proper motion (μ) RA: +85.393[1] mas/yr
Dec.: −14.869[1] mas/yr
Parallax (π)22.4141 ± 0.4969[1] mas
Distance146 ± 3 ly
(44.6 ± 1.0 pc)
Absolute magnitude (MV)1.10[6]
Mass1.94[6] M
Radius3.34[3] R
Surface gravity (log g)3.73[7] cgs
Temperature7,543[3] K
Rotation14.2[6] d
Rotational velocity (v sin i)192[6] km/s
Age966[7] Myr
Other designations
71 Tau, V777 Tau, BD+15°625, GC 5375, HD 28052, HIP 20713, HR 1394, SAO 93932[8]
Database references

71 Tauri is a suspected triple star[9] system in the zodiac constellation Taurus, located 146 light years from the Sun.[1] It is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of +4.48.[2] The star is moving further away from the Earth with a heliocentric radial velocity of +38 km/s.[5] It is a member of the Hyades open cluster.[10]

The primary component is an F-type main-sequence star with a stellar classification of F0 V.[3] It is a Delta Scuti variable with an amplitude of 0.02 in magnitude and a frequency of 0.16 d−1.[4] This star has about 1.94[6] times the mass of the Sun and 3.34[3] times the Sun's radius. It has a projected rotational velocity of 192 km s−1, for an estimated rotation period of 14.2 days.[6] Extreme ultraviolet flares have been observed coming from this star's hot corona,[3] and it is the second brightest X-ray source in the Hyades.[10]


  1. ^ a b c d e f 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.
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ a b c d e f Mullan, D. J.; Mathioudakis, M. (November 2000), "Extreme-Ultraviolet Flares in an F2 Star", The Astrophysical Journal, 544 (1): 475–480, Bibcode:2000ApJ...544..475M, doi:10.1086/317202.
  4. ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  5. ^ a b Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
  6. ^ a b c d e f Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628, Bibcode:2000A&A...361..614P.
  7. ^ a b David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  8. ^ "71 Tau -- Variable Star of delta Sct type", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2007-01-25
  9. ^ 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.
  10. ^ a b Simon, Theodore; Ayres, Thomas R. (August 2000), "71 Tauri: Hyades Enigma Resolved?", The Astrophysical Journal, 539 (1): 325–330, Bibcode:2000ApJ...539..325S, doi:10.1086/309228.