104 Tauri


104 Tauri
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 05h 07m 27.00529s[1]
Declination +18° 38′ 42.1815″[1]
Apparent magnitude (V) 4.92[2]
Spectral type G4V[3]
B−V color index 0.64[3]
Radial velocity (Rv)+20.19[3] km/s
Proper motion (μ) RA: +534.73[1] mas/yr
Dec.: +17.93[1] mas/yr
Parallax (π)64.79 ± 0.33[1] mas
Distance50.3 ± 0.3 ly
(15.43 ± 0.08 pc)
Absolute magnitude (MV)3.75±0.06[4]
[4] M
Radius1.63±0.06[4] R
Luminosity2.41[5] L
Surface gravity (log g)4.06[2] cgs
Temperature5,717[2] K
Metallicity [Fe/H]−0.22[2] dex
Rotational velocity (v sin i)10.00[3] km/s
Age10.15[2] Gyr
Other designations
m Tau, 104 Tau, BD+18° 779, GJ 188, HD 32923, HIP 23835, HR 1656, SAO 94332[6]
Database references

104 Tauri (104 Tau) is the Flamsteed designation for a star in the equatorial constellation of Taurus. It has an apparent magnitude of 4.92, which is bright enough to be seen with the naked eye. Based upon parallax measurements, this star is located about 50 light-years from the Sun.[1] It is moving further from the Sun with a heliocentric radial velocity of +20 km/s.[3]

This star has a stellar classification of G4 V,[3] which suggests it is an ordinary G-type main-sequence star that is generating energy through hydrogen fusion at its stellar core. It is an estimated 10[2] billion years old and is spinning with a projected rotational velocity of 10 km/s.[3] The star has about the same mass as the Sun, with 1.6 times the Sun's radius.[4] It is radiating 2.4[5] times the Sun's luminosity from its photosphere at an effective temperature of 5,717 K.[2]

The apparent brightness of this star indicates that it is a young, population I star. However, the chemical abundances in its outer atmosphere tell a different story, suggesting that it is a population II star with an age of 12−13 billion years. This discrepancy may indicate that the star has undergone a period of mass accretion. Possible scenarios indicate that the star has either undergone a merger with a close companion, or else interacted with the progenitor cloud of the nearby open cluster NGC 2516.[7]

The star displays convincing evidence for an infrared excess, suggesting the presence of a circumstellar debris disk of dust.[8]


  1. ^ a b c d e f van Leeuwen, F. (November 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 Ramírez, I.; et al. (February 2013), "Oxygen abundances in nearby FGK stars and the galactic chemical evolution of the local disk and halo", The Astrophysical Journal, 764 (1): 78, arXiv:1301.1582, Bibcode:2013ApJ...764...78R, doi:10.1088/0004-637X/764/1/78, S2CID 118751608.
  3. ^ a b c d e f g White, Russel J.; et al. (June 2007), "High-Dispersion Optical Spectra of Nearby Stars Younger Than the Sun", The Astronomical Journal, 133 (6): 2524–2536, arXiv:0706.0542, Bibcode:2007AJ....133.2524W, doi:10.1086/514336, S2CID 122854.
  4. ^ a b c d Bernkopf, Jan; Fuhrmann, Klaus (June 2006), "Local subgiants and time-scales of disc formation", Monthly Notices of the Royal Astronomical Society, 369 (2): 673–676, Bibcode:2006MNRAS.369..673B, doi:10.1111/j.1365-2966.2006.10326.x.
  5. ^ 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.
  6. ^ "m Tau -- Double or multiple star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2013-08-12.
  7. ^ Fuhrmann, K.; et al. (December 2012), "Archeology of an Ancient Star", The Astrophysical Journal, 761 (2): 8, Bibcode:2012ApJ...761..159F, doi:10.1088/0004-637X/761/2/159, 159.
  8. ^ Holmes, E. K.; et al. (June 2003), "A Survey of Nearby Main-Sequence Stars for Submillimeter Emission", The Astronomical Journal, 125 (6): 3334–3343, Bibcode:2003AJ....125.3334H, doi:10.1086/375202.