  | |
| Observation data EpochJ2000.0 EquinoxJ2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 15m 37.89982s[1] |
| Declination | −20° 39′ 06.1032″[1] |
| Apparent magnitude (V) | +5.16[2] |
| Characteristics | |
| Spectral type | K0 II-III[3] |
| B−Vcolor index | +1.15[2] |
| Astrometry | |
| Radial velocity (Rv) | −4.5±0.5[4] km/s |
| Proper motion (μ) | RA: +15.01[1]mas/yr Dec.: −2.07[1]mas/yr |
| Parallax (π) | 5.07±0.25 mas[1] |
| Distance | 640 ± 30 ly (197 ± 10 pc) |
| Absolute magnitude (MV) | −1.16±0.107[5] |
| Details | |
| Mass | 2.63[6] M☉ |
| Luminosity | 447[6] L☉ |
| Surface gravity (log g) | 1.77[5] cgs |
| Temperature | 4,490±25[6] K |
| Metallicity [Fe/H] | −0.15[5] dex |
| Rotational velocity (v sin i) | 3.8[7] km/s |
| Age | 1.24[6] Gyr |
| Other designations | |
| φ Cap,28 Cap,BD−21°5974,HD 202320,HIP 104963,HR 8127,SAO 190173[8] | |
| Database references | |
| SIMBAD | data |
Phi Capricorni (φ Cap, φ Capricorni) is a solitary[9]star in the southernconstellation ofCapricornus. It is visible to the naked eye with anapparent visual magnitude of +5.16.[2] Based upon an annualparallax shift of 5.07 mas as seen from the Earth,[1] the star is located about 640 light years from theSun, give or take 30 light years.
This is anevolved, orange-huedK-typegiant/bright giant star with astellar classification of K0 II-III[3] It shows aninfrared excess, which may be due to leftover material from a mass-loss event.[7] The star has an estimated 2.63 times themass of the Sun,[6] and radiates 447 times thesolar luminosity from itsphotosphere at aneffective temperature of 4,490 K.[6] Phi Capricorni is around 1.24[6] billion years old and is spinning with aprojected rotational velocity of 3.8 km/s.[7]
InChinese,十二國 (Shíer Guó), meaningTwelve States, refers to an asterism which is represent twelve ancient states in theSpring and Autumn period and theWarring States period, consisting of φ Capricorni,ι Capricorni,38 Capricorni,35 Capricorni,36 Capricorni,χ Capricorni,θ Capricorni,30 Capricorni,33 Capricorni,ζ Capricorni,19 Capricorni,26 Capricorni,27 Capricorni,20 Capricorni,η Capricorni and21 Capricorni.[10] Consequently, theChinese name for φ Capricorni itself represents the stateChu (楚),[11] together withε Ophiuchi inRight Wall of Heavenly Market Enclosure (asterism).[12][13]
R. H. Allen had opinion that φ Capricorni, together withχ Capricorni, represented the stateWei (魏).[13]
