Phi1 Hydrae
Star in the constellation Hydra
From Wikipedia, the free encyclopedia
Phi1 Hydrae, Latinized from φ1 Hydrae, is a yellow-hued star in the constellation Hydra. Its apparent magnitude is 7.61,[2] making it too faint to be seen with the naked eye. Based upon an annual parallax shift of 12.3 mas as seen from Earth,[1] it is located about 266 light-years from the Sun. It forms a triangle with the brighter φ2 Hydrae and φ3 Hydrae, between μ Hydrae and ν Hydrae.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hydra |
| Right ascension | 10h 32m 41.16026s[1] |
| Declination | −16° 57′ 31.4110″[1] |
| Apparent magnitude (V) | 7.61[2] |
| Characteristics | |
| Spectral type | G2 V[3] |
| Astrometry | |
| Radial velocity (Rv) | +15.8±0.3[4] km/s |
| Proper motion (μ) | RA: −20.964[5] mas/yr Dec.: −87.082[5] mas/yr |
| Parallax (π) | 12.2814±0.0688 mas[5] |
| Distance | 266 ± 1 ly (81.4 ± 0.5 pc) |
| Absolute magnitude (MV) | +3.30[6] |
| Details[7] | |
| Mass | 1.34 M☉ |
| Radius | 2.1[5] R☉ |
| Luminosity | 4.4[6] L☉ |
| Surface gravity (log g) | 3.90±0.08 cgs |
| Temperature | 5,992±50 K |
| Metallicity [Fe/H] | +0.15±0.05 dex |
| Age | 4.1 Gyr |
| Other designations | |
| φ1 Hya, 43 Hydrae, BD−16°3078, HD 91369, HIP 51614, SAO 156047[8] | |
| Database references | |
| SIMBAD | data |
Phi1 Hydrae is an ordinary G-type main-sequence star, having a Sun-like stellar classification of G2 V and a photospheric temperature only slightly higher than the sun.[3] However, the mass is 34%[7] greater than the Sun, and it is radiating 4.4 times the Sun's luminosity.[6] Phi1 Hydrae is moving further from the Sun with a radial velocity of +15.8 km/s.[4]