51 Eridani

51 Eridani
Location of 51 Eridani (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Eridanus
Right ascension 04h 37m 36.13261s
Declination −02° 28′ 24.7757″
Apparent magnitude (V) 5.22
Characteristics
Evolutionary stage main sequence
Spectral type F0 V
Variable type γ Dor
Astrometry
Radial velocity (Rv)12.60±0.3 km/s
Proper motion (μ) RA: +44.049 mas/yr
Dec.: –64.028 mas/yr
Parallax (π)33.4390±0.0777 mas
Distance97.5 ± 0.2 ly
(29.91 ± 0.07 pc)
Absolute magnitude (MV)2.87
Details
51 Eri A
Mass1.550+0.006
−0.005
 M
Radius1.45±0.02 R
Luminosity5.72±0.096 L
Surface gravity (log g)3.95±0.04 cgs
Temperature7,422±58 K
Metallicity [Fe/H]−0.12±0.06 dex
Rotational velocity (v sin i)77.9 km/s
Age23.2+1.7
−2.0
 Myr
Other designations
c Eridani, 51 Eridani, BD−02°963, HD 29391, HIP 21547, HR 1474, SAO 131358, 2MASS J04373613-0228248
Database references
SIMBADdata
Exoplanet Archivedata

51 Eridani is a star in the constellation Eridanus. It has an apparent magnitude of 5.22, meaning it is just visible to the unaided eye in suburban and rural skies. The primary star's absolute magnitude is 2.87. There is also a binary star named GJ 3305 which shares the same proper motion through space with it, making it overall a triple star system.

The primary star is significant as the host to one of the first planets to have been directly imaged in a wide orbit, and the first detected by the Gemini Planet Imager.