136 Tauri


136 Tauri
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 05h 53m 19.64606s[1]
Declination +27° 36′ 44.1378″[1]
Apparent magnitude (V) 4.56[2]
Spectral type A0 V[3] (A0 V + A0 V)[2]
B−V color index −0.008±0.009[2]
Variable type suspected[4]
Radial velocity (Rv)−17.2±4.2[5] km/s
Proper motion (μ) RA: +3.72[1] mas/yr
Dec.: −10.11[1] mas/yr
Parallax (π)7.71 ± 0.22[1] mas
Distance420 ± 10 ly
(130 ± 4 pc)
Absolute magnitude (MV)−1.00[2]
Period (P)5.969 d
Eccentricity (e)0.00
Periastron epoch (T)2,420,147.25±10.0 JD
Argument of periastron (ω)
Semi-amplitude (K1)
48.9 km/s
Semi-amplitude (K2)
71.0 km/s
136 Tau A
Radius2.1[7] R
Luminosity197.19[8] L
Temperature8,732[8] K
Rotational velocity (v sin i)10[9] km/s
Other designations
136 Tau, BD+27° 899, HD 39357, HIP 27830, HR 2034, SAO 77675[10]
Database references

136 Tauri is a white-hued binary star system in the zodiac constellation of Taurus. It has a combined apparent visual magnitude of 4.56,[2] which is bright enough to be faintly visible to the naked eye. Based upon an annual parallax shift of 7.71±0.22 mas as seen from Earth's orbit,[1] it is located approximately 420 light years from the Sun. The system is moving nearer with a heliocentric radial velocity of −17.2 km/s,[5] and is expected to make its closest approach in 6.5 million years at a distance of 150 ly (45 pc).[2]

This is a close, double-lined spectroscopic binary with an orbital period of 5.96 days and an eccentricity of 0.00.[6] Tidal effects between the pair may have circularized their orbit and slowed their rotation rates – the primary has a projected rotational velocity of 10 km/s.[9] They have a combined stellar classification of A0 V,[3] and both are most likely A-type main-sequence stars of the same class.[2]


  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.
  2. ^ a b c d e f g 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.
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  4. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ a b De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347.
  6. ^ a b Luyten, W. J. (July 1936), "A rediscussion of the orbits of seventy-seven spectroscopic binaries", Astrophysical Journal, 84: 85, Bibcode:1936ApJ....84...85L, doi:10.1086/143751.
  7. ^ Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy & Astrophysics (3rd ed.), 367: 521–24, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  8. ^ a b McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–357, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  9. ^ a b Abt, Helmut A.; Boonyarak, Chayan (November 2004), "Tidal Effects in Binaries of Various Periods", The Astrophysical Journal, 616 (1): 562–566, Bibcode:2004ApJ...616..562A, doi:10.1086/423795.
  10. ^ "136 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-30.