 HIP 102152 Credit:ESO/Digitized Sky Survey 2 | |
| Observation data EpochJ2000.0 EquinoxJ2000.0 (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 20h 41m 54.6336s[1] |
| Declination | −27° 12′ 57.4154″[1] |
| Apparent magnitude (V) | 9.15±0.02[2] |
| Characteristics | |
| Spectral type | G3 V[3] |
| U−Bcolor index | +0.30[4] |
| B−Vcolor index | +0.65[2] |
| Astrometry | |
| Radial velocity (Rv) | −43.9±0.3[5] km/s |
| Proper motion (μ) | RA: +175.628[1]mas/yr Dec.: −15.593[1]mas/yr |
| Parallax (π) | 12.7715±0.0164 mas[1] |
| Distance | 255.4 ± 0.3 ly (78.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.74[6] |
| Details | |
| Mass | 0.97[7] M☉ |
| Radius | 1.08+0.07 −0.05[8] R☉ |
| Luminosity | 1.19[6] L☉ |
| Surface gravity (log g) | 4.40±0.02[9] cgs |
| Temperature | 5718±5[9] K |
| Metallicity [Fe/H] | −0.020±0.005[9] dex |
| Rotational velocity (v sin i) | 1.78±0.12[9] km/s |
| Age | 6.92±0.69[9] Gyr |
| Other designations | |
| CD−27°14976,CPD−27°7079,HD 197027,HIP 102152,SAO 189585[10] | |
| Database references | |
| SIMBAD | data |
HD 197027 (HIP 102152) is astar in theconstellationCapricornus. It has anapparent magnitude of 9.15,[2] making it readily visible through atelescope but not to thenaked eye. The object is located at a distance of 255light years but is approaching theSolar System with a heliocentricradial velocity of−44 km/s.[5]
HD 197027 has astellar classification of G3 V, indicating that it is an ordinaryG-type main-sequence star like theSun. It has only 97% themass of the Sun[7] but 108% of its radius.[8] It shines at 119% theluminosity of the Sun[6] from itsphotosphere at aneffective temperature of 5,718K,[9] similar to the Sun's 5,778 K. HD 197027'smetallicity – elements heavier thanhelium – is similar to the Sun.[9] At an older age of 6.92billion years, it spins with aprojected rotational velocity of about2 km/s.[9]
Since its measured properties of this star are very similar to those of the Sun, it has been considered a candidate oldersolar twin.[11] The abundances of 21elements overall are more similar to the Sun than any other known solar twin.[citation needed] Its Iron Abundance is -0.03 with an error value of 0.02 Fe/H. (The value comes from the Hipparcos Extended Catalog.)[12]
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