| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 20h37m 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] |
| Distance | 750 ± 4 ly (230 ± 1 pc) |
| Absolute magnitude (MV) | −0.27[2] |
| Details | |
| Mass | 1.18[6] M☉ |
| Radius | 25[7] R☉ |
| Luminosity | 191[7] L☉ |
| Surface gravity (log g) | 1.81[6] cgs |
| Temperature | 4,272[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 | |
| SIMBAD | data |
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 velocityof18.5 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 temperatureof4272 K.[6] τ1 Cap's metallicity – elements heavier than helium – is at solar level.[6]
|
| |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
| Stars |
| ||||||||||||
| |||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||
| |||||||||||||
