Tau Centauri

Not to be confused with T Centauri.
τ Centauri
Location of τ Centauri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Centaurus
Right ascension 12h 37m 42.16377s[1]
Declination −48° 32′ 28.6899″[1]
Apparent magnitude (V) +3.86[2]
Characteristics
Spectral type A0 V[3] or A1 IVnn[4]
U−B color index +0.04[2]
B−V color index +0.06[2]
Astrometry
Radial velocity (Rv)+5.5±2.3[5] km/s
Proper motion (μ) RA: −186.26[1] mas/yr
Dec.: −6.01[1] mas/yr
Parallax (π)24.85 ± 0.53 mas[1]
Distance131 ± 3 ly
(40.2 ± 0.9 pc)
Absolute magnitude (MV)+0.83[6]
Details
Mass2.31[7] M☉
Radius2.2[8] R☉
Luminosity42[6] L☉
Surface gravity (log g)4.02±0.14[7] cgs
Temperature10,533±358[7] K
Rotational velocity (v sin i)296.8±3.8[9] km/s
Age132[7] Myr
Other designations
τ Cen, CD−47° 7745, HD 109787, HIP 61622, HR 4802, SAO 223560[10]
Database references
SIMBADdata

Tau Centauri, Latinized from τ Centauri, is a solitary[11] star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.86.[2] The distance to this star, based upon an annual parallax shift of 24.85 mas,[1] is 131 light years. There is a 98% chance that it is a co-moving companion of Gamma Centauri; the two stars have an estimated separation of 1.7 ly (0.53 pc).[12]

This is an A-type star with stellar classifications of A0 V[3] or A1 IVnn,[4] indicating it may be a main sequence star or a more evolved subgiant star. It is around 132[7] million years old and is spinning rapidly with a projected rotational velocity of 296.8[9] km/s. This is giving the star an oblate shape, with an estimated equatorial girth that is 30% larger than the polar radius.[13] The star has an estimated 2.3[7] times the mass of the Sun and 2.2[8] times the Sun's radius.

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Lagrange2009 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gray2003 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d e f Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Diaz2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference DeRosa2014 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Shaya2011 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference belle2012 was invoked but never defined (see the help page).