Sigma Capricorni
Star in the constellation Capricornus
From Wikipedia, the free encyclopedia
Sigma Capricorni is a solitary,[8] orange-hued star in the southern constellation of Capricornus,[7] 0.5 degree north of the ecliptic. Its name is a Bayer designation that is Latinized from σ Capricorni, and abbreviated Sigma Cap or σ Cap. This star is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.31.[3] The star is about 950 ly (290 pc) 1,070 light years away from the Sun based on parallax, but is drifting closer with a radial velocity of −9.6 km/s.[5]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus[1] |
| Right ascension | 20h 19m 23.604s[2] |
| Declination | −19° 07′ 06.69″[2] |
| Apparent magnitude (V) | +5.31[3] |
| Characteristics | |
| Spectral type | K2 III[4] |
| U−B color index | +1.56[3] |
| B−V color index | +1.43[3] |
| Astrometry | |
| Radial velocity (Rv) | −9.64±0.16[5] km/s |
| Proper motion (μ) | RA: +5.034 mas/yr[2] Dec.: −10.825 mas/yr[2] |
| Parallax (π) | 3.4448±0.0987 mas[2] |
| Distance | 950 ± 30 ly (290 ± 8 pc) |
| Absolute magnitude (MV) | −2.38[1] |
| Details | |
| Mass | 6.3±0.7[6] M☉ |
| Radius | 67.5+4.2 −6.0[5] R☉ |
| Luminosity | 1,392±64[5] L☉ |
| Temperature | 4,292+204 −127[5] K |
| Age | 60.5±17.2[6] Myr |
| Other designations | |
| σ Cap, CD−19°5776, FK5 3625, HD 193150, HIP 100195, HR 7761, SAO 163445, WDS J20194-1907A[7] | |
| Database references | |
| SIMBAD | data |
This is an evolved, K-type giant star with a stellar classification of K2 III.[4] Having exhausted the supply of hydrogen at its core, it has expanded and now has around 67.5[5] times the girth of the Sun. The star is about 60.5[6] million years old with 6.3[6] times the mass of the Sun. It is radiating 1,392[5] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,292 K.[5]
A magnitude 9.43 visual companion is at an angular separation of 55.90″ along a position angle of 179°, as of 2016.[9]