Tau Tauri


Tau Tauri
Taurus constellation map.svg
Red circle.svg
Location of τ Tauri (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 04h 42m 14.70161s[1]
Declination 22° 57′ 24.9214″[1]
Apparent magnitude (V) 4.27[2]
Spectral type B3V[3] + ? + A0V–A2V[4] + A1V[5]
U−B color index -0.57[6]
B−V color index -0.14[6]
Radial velocity (Rv)+14.60[7] km/s
Proper motion (μ) RA: -2.89[1] mas/yr
Dec.: -21.86[1] mas/yr
Parallax (π)8.19 ± 0.88[1] mas
Distanceapprox. 400 ly
(approx. 120 pc)
Absolute magnitude (MV)-1.15[2]
Period (P)2.956549±0.000002 d
Semi-major axis (a)≤ 0.01455 AU
Eccentricity (e)0.051±0.019
Periastron epoch (T)2,436,424.207±0.009 JD
Argument of periastron (ω)
Semi-amplitude (K1)
53.6±1.0 km/s
Mass6.4[9] M
Luminosity1,472[10] L
Surface gravity (log g)2.60[11] cgs
Temperature18,700[10] K
Metallicity [Fe/H]-0.51[11] dex
Rotational velocity (v sin i)115[12] km/s
Other designations
τ Tau, 94 Tauri, BD+22°739, FK5 174, GC 5716, HD 29763, HIP 21881, HR 1497, SAO 76721, CCDM J04422+2257AB, WDS J04422+2257A, GSC 01830-02129[13]
Database references

Tau Tauri, Latinized from τ Tauri, is a quadruple star system[5] in the constellation Taurus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.33.[14] The distance to this system is approximately about 400 light years based on parallax.[1] The system is moving further from the Earth with a heliocentric radial velocity of +14.6 km/s,[7] and it is a member of the Taurion OB association, located between Orion and Taurus.[15] It is located 0.7 degree north of the ecliptic, and thus is subject to lunar occultations.[4]

The blue-white hued primary, component Aa, is a B-type main-sequence star with a stellar classification of B3V.[3] It was found to be a close spectroscopic binary in 1903 by American astronomers Edwin B. Frost and Walter S. Adams. The pair have an orbital period of 2.96 days and eccentricity of 0.05.[8] A second companion, white-hued component Ab, has magnitude 6.97 and angular separation 0.2" from the primary in a 58-year orbit.[16][5] This is a probably A-type main-sequence star with a class of A0V–A2V.[4] The more distant component B is a type A1V star with magnitude 7.2 and separation 62.8".[5]


  1. ^ a b c d e f 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. ^ 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. Vizier catalog entry
  3. ^ a b 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. ^ a b c Richichi, A.; et al. (June 1994). "New binary stars discovered by lunar occultations". Astronomy and Astrophysics. 286: 829–837. Bibcode:1994A&A...286..829R.
  5. ^ a b c d Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976. Vizier catalog entry
  6. ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  7. ^ a b Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution for Science. Bibcode:1953GCRV..C......0W. ISBN 9780598216885. LCCN 54001336.
  8. ^ a b Petrie, R. M.; Ebbighausen, E. G. (1961). "The spectroscopic binary Boss 1107". Publications of the Dominion Astrophysical Observatory Victoria. 11: 385–394. Bibcode:1961PDAO...11..385P.
  9. ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873. Vizier catalog entry
  10. ^ a b Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. S2CID 111387483. Vizier catalog entry
  11. ^ a b Wu, Yue; Singh, H. P.; Prugniel, P.; Gupta, R.; Koleva, M. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics. 525: A71. arXiv:1009.1491. Bibcode:2011A&A...525A..71W. doi:10.1051/0004-6361/201015014. S2CID 53480665.
  12. ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573 (1): 359–365. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.
  13. ^ "tau Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-18.{{cite web}}: CS1 maint: postscript (link)
  14. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
  15. ^ Bouy, H.; Alves, J. (December 2015). "Cosmography of OB stars in the solar neighbourhood". Astronomy & Astrophysics. 584: 13. Bibcode:2015A&A...584A..26B. doi:10.1051/0004-6361/201527058. A26.
  16. ^ Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: A69. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. Vizier catalog entry