Phi1 Hydrae

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.

For other stars with this Bayer designation, see φ Hydrae

Phi¹ 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]