Tau Andromedae

Not to be confused with T Andromedae.
Tau Andromedae
Location of τ Andromedae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 01h 40m 34.81619s[1]
Declination +40° 34′ 37.3397″[1]
Apparent magnitude (V) +4.94[2]
Characteristics
Spectral type B5 III[3]
U−B color index −0.41[2]
B−V color index −0.09[2]
Astrometry
Radial velocity (Rv)−13.9±2.6[4] km/s
Proper motion (μ) RA: 17.889(178)[1] mas/yr
Dec.: −20.981(95)[1] mas/yr
Parallax (π)4.7804 ± 0.1304 mas[1]
Distance680 ± 20 ly
(209 ± 6 pc)
Details
Luminosity851[5] L☉
Surface gravity (log g)3.357±0.020[6] cgs
Temperature12,680±100[6] K
Rotational velocity (v sin i)74±13[6] km/s
Age217[7] Myr
Other designations
τ And, 53 And, BD+39 378, HD 10205, HIP 7818, HR 477, SAO 37418, PPM 44297[8]
Database references
SIMBADdata

Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single[9] star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94,[2] which is bright enough to be viewed from dark suburban skies. From parallax measurements made during the Gaia mission, the distance to this star can be estimated as roughly 680 light-years (210 parsecs) from Earth. The brightness of this star is diminished by 0.24 in magnitude due to extinction caused by intervening gas and dust.[3] It is drifting closer to the Sun with a radial velocity of −14 km/s.[4]

The spectrum of this star matches a stellar classification of B5 III,[3] with the luminosity class of III indicating that this is a giant star. It is radiating about 851 times the luminosity of the Sun[5] from its photosphere at an effective temperature of 12,670 K.[6] The star is an estimated 217[7] million years old and is spinning with a high projected rotational velocity of ~74 km/s.[6]

  1. ^ a b c d e Cite error: The named reference Gaia EDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference apj694_2_1085 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference apjss176_1_276 was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference Huang_et_al_2010 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggleton_Tokovinin_2008 was invoked but never defined (see the help page).