Tau1 Capricorni

For other stars with this Bayer designation, see τ Capricorni.
τ1 Capricorni
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Capricornus
Right ascension 20h 37m 21.20s[1]
Declination −15° 08′ 50.4″[1]
Apparent magnitude (V) +6.76[2]
Characteristics
Spectral type K1 III[3]
U−B color index +1.23[4]
B−V color index +1.26[4]
Astrometry
Radial velocity (Rv)18.5 ± 3[5] km/s
Proper motion (μ) RA: 61.508[1] mas/yr
Dec.: −47.081[1] mas/yr
Parallax (π)4.3504 ± 0.0229 mas[1]
Distance750 ± 4 ly
(230 ± 1 pc)
Absolute magnitude (MV)−0.27[2]
Details
Mass1.18[6] M☉
Radius25[7] R☉
Luminosity191[7] L☉
Surface gravity (log g)1.81[6] cgs
Temperature4,272[6] K
Metallicity [Fe/H]−0.02[6] dex
Other designations
τ1 Cap, 13 Capricorni, 34 G. Capricorni, BD−15°5732, GC 28694, HD 196348, HIP 101751, SAO 163740
Database references
SIMBADdata

Tau1 Capricorni (τ1 Cap, τ1 Capricorni) is a star in the constellation Capricornus. It has an apparent magnitude of 6.76,[2] making it readily visible in binoculars, but not to the naked eye. Located approximately 750 light years from Earth,[1] the star is receding with a heliocentric radial velocity of 18.5 km/s.[5] Due to its location near the ecliptic, τ1 Cap can be occulted by the Moon and rarely planets.[8]

τ1 Capricorni has a stellar classification of K1 III, indicating that it is an ageing K-type giant.[3] At present it has 118% the mass of the Sun[6] and an enlarged radius of 25 solar radii.[7] It shines at 191 times the luminosity of the Sun[7] from its photosphere at an effective temperature of 4272 K.[6] τ1 Cap's metallicity – elements heavier than helium – is at solar level.[6]

  1. ^ a b c d e f Cite error: The named reference edr3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1988 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference starhorse was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference tic was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Radick1980 was invoked but never defined (see the help page).