5 Tauri


5 Tauri
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 03h 30m 52.38296s[1]
Declination +12° 56′ 12.0489″[1]
Apparent magnitude (V) +4.14[2]
Spectral type K0-III[3]
U−B color index +0.95[4]
B−V color index +1.09[4]
Radial velocity (Rv)14.2±0.3[2] km/s
Proper motion (μ) RA: 13.537[1] mas/yr
Dec.: -2.037[1] mas/yr
Parallax (π)6.1081 ± 0.3907[1] mas
Distance530 ± 30 ly
(160 ± 10 pc)
Absolute magnitude (MV)−0.96[2]
Primary5 Tauri A
Companion5 Tauri B
Period (P)960 days
Semi-major axis (a)4.25 mas[6]
Eccentricity (e)0.397±0.016
Inclination (i)36.95[6]°
Longitude of the node (Ω)207.61[6]°
Periastron epoch (T)2,414,889.565±5.82
Argument of periastron (ω)
Semi-amplitude (K1)
8.25±0.15 km/s
5 Tauri A
Mass4.0±0.7[7] M
Radius8.5[8] R
Luminosity329.38[2] L
Surface gravity (log g)1.97[9] cgs
Temperature4,644[9] K
Metallicity [Fe/H]0.05[9] dex
Rotational velocity (v sin i)10[10] km/s
5 Tauri B
Mass1.13±0.13 M
Other designations
f Tau, 5 Tau, BD+12°486, FK5 125, GC 4184, HD 21754, HIP 16369, HR 1066, SAO 93469, TYC 656-1725-1[11]
Database references

5 Tauri is a binary star[6] in the zodiac constellation of Taurus, located approximately 530 light years from the Sun. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of +4.14. It is moving further from the Earth with a heliocentric radial velocity of +14 km/s.[2]

This is a spectroscopic binary with a period of 960 days and an eccentricity of about 0.4.[5] The primary component is a K-type giant with a stellar classification of K0-III.[3] It has four[7] times the mass of the Sun and is radiating 329[2] times the Sun's luminosity from its photosphere at an effective temperature of 4,644 K.[9]


  1. ^ a b c d e 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 e f 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 Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  4. ^ 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.
  5. ^ a b Harper, W. E. (June 1924). "The orbit of the spectroscopic binary 5 Tauri". Publications of the Dominion Observatory Ottawa. 3: 145–149. Bibcode:1924PDAO....3..145H.
  6. ^ a b c d ESA (1997). "The Hipparcos and Tycho Catalogues". VizieR On-line Data Catalog. Bibcode:1997yCat.1239....0E.
  7. ^ a b Pourbaix, D.; Boffin, H. M. J. (February 2003), "Reprocessing the Hipparcos Intermediate Astrometric Data of spectroscopic binaries. II. Systems with a giant component", Astronomy and Astrophysics, 398 (3): 1163–1177, arXiv:astro-ph/0211483, Bibcode:2003A&A...398.1163P, doi:10.1051/0004-6361:20021736, S2CID 12361870
  8. ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  9. ^ a b c d Earle Luck, R. (2014). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137.
  10. ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
  11. ^ "5 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 December 2016.

External links

  • "HD 21754 -- Spectroscopic binary". SIMBAD Astronomical Database. Retrieved 2007-01-26.