Astronomy:Tau Tauri

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Tau Tauri
Taurus constellation map.svg
Red circle.svg
Location of τ Tauri (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Taurus
Right ascension  04h 42m 14.70161s[1]
Declination 22° 57′ 24.9214″[1]
Apparent magnitude (V) 4.27[2]
Characteristics
Spectral type B3V[3] + ? + A0V–A2V[4] + A1V[5]
U−B color index -0.57[6]
B−V color index -0.14[6]
Astrometry
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]
Orbit[8]
PrimaryAa
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)
(secondary)
126.7±21.8°
Semi-amplitude (K1)
(primary)
53.6±1.0 km/s
Details
Aa
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
SIMBADdata

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]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry
  2. 2.0 2.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  Vizier catalog entry
  3. 3.0 3.1 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. Bibcode1995yCat.5050....0H. 
  4. 4.0 4.1 4.2 Richichi, A. et al. (June 1994). "New binary stars discovered by lunar occultations". Astronomy and Astrophysics 286: 829–837. Bibcode1994A&A...286..829R. 
  5. 5.0 5.1 5.2 5.3 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E.  Vizier catalog entry
  6. 6.0 6.1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers 42 (2): 443. Bibcode2014JAVSO..42..443M. Vizier catalog entry
  7. 7.0 7.1 Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication (Carnegie Institution for Science). ISBN 9780598216885. Bibcode1953GCRV..C......0W. 
  8. 8.0 8.1 Petrie, R. M.; Ebbighausen, E. G. (1961). "The spectroscopic binary Boss 1107". Publications of the Dominion Astrophysical Observatory Victoria 11: 385–394. Bibcode1961PDAO...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. doi:10.1111/j.1365-2966.2010.17434.x. Bibcode2011MNRAS.410..190T.  Vizier catalog entry
  10. 10.0 10.1 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. doi:10.1002/asna.200911355. Bibcode2010AN....331..349H.  Vizier catalog entry
  11. 11.0 11.1 Wu, Yue; Singh, H. P.; Prugniel, P.; Gupta, R.; Koleva, M. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics 525: A71. doi:10.1051/0004-6361/201015014. Bibcode2011A&A...525A..71W. 
  12. Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal 573 (1): 359–365. doi:10.1086/340590. Bibcode2002ApJ...573..359A. 
  13. "tau Tau". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tau+Tau. 
  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. doi:10.1086/323920. Bibcode2001AJ....122.3466M.  Vizier catalog entry
  15. Bouy, H.; Alves, J. (December 2015). "Cosmography of OB stars in the solar neighbourhood". Astronomy & Astrophysics 584: 13. doi:10.1051/0004-6361/201527058. A26. Bibcode2015A&A...584A..26B. 
  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. doi:10.1051/0004-6361/201219774. Bibcode2012A&A...546A..69M.  Vizier catalog entry