Upsilon Capricorni
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 20h 40m 02.94518s |
| Declination | −18° 08′ 19.1664″ |
| Apparent magnitude (V) | 5.17 |
| Characteristics | |
| Spectral type | M1 III |
| B−V color index | +1.65 |
| Astrometry | |
| Radial velocity (Rv) | −12.3±1.6 km/s |
| Proper motion (μ) | RA: −22.764 mas/yr Dec.: −22.170 mas/yr |
| Parallax (π) | 5.1719±0.1354 mas |
| Distance | 630 ± 20 ly (193 ± 5 pc) |
| Absolute magnitude (MV) | −1.09 |
| Details | |
| Radius | 92±4 R☉ |
| Luminosity | 1,283.0±76.5 L☉ |
| Temperature | 3,953+427 −193 K |
| Metallicity [Fe/H] | −0.08 dex |
| Other designations | |
| υ Cap, 15 Capricorni, NSV 25208, BD−18°5738, FK5 773, HD 196777, HIP 101984, HR 7900, SAO 163779 | |
| Database references | |
| SIMBAD | data |
Upsilon Capricorni, Latinized from υ Capricorni, is a solitary star in the southern constellation of Capricornus. It has a reddish hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.17. The star is about 630 light years away based on parallax, but is drifting closer with a radial velocity of −12 km/s. It is 0.22 degree north of the ecliptic, so is subject to lunar occultations.
This is an aging red giant star on the asymptotic giant branch with a stellar classification of M1 III, a star that has exhausted the supply of hydrogen at its core then cooled and expanded. It has 92 times the radius of the Sun and is radiating 1,283 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,953 K.
It is a suspected variable star of unknown type with a brightness that has been measured ranging from a peak of 5.19 down to 5.24.