7 Persei

7 Persei
Location of 7 Persei (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Perseus
Right ascension 02h 18m 04.58456s
Declination +57° 30 58.7594
Apparent magnitude (V) 5.99
Characteristics
Evolutionary stage horizontal branch
Spectral type G7 III
B−V color index 1.039±0.007
Astrometry
Radial velocity (Rv)−12.5±0.3 km/s
Proper motion (μ) RA: −13.409 mas/yr
Dec.: −1.338 mas/yr
Parallax (π)4.1956±0.0322 mas
Distance777 ± 6 ly
(238 ± 2 pc)
Absolute magnitude (MV)−1.22
Details
Mass3.84 M
Radius24 R
Luminosity316 L
Surface gravity (log g)2.44 cgs
Temperature4,974 K
Metallicity [Fe/H]−0.11 dex
Rotational velocity (v sin i)11.5 km/s
Age191 Myr
Other designations
7 Per, BD+56°486, HD 13994, HIP 10729, HR 662, SAO 23149
Database references
SIMBADdata

7 Persei is a star in the constellation Perseus, located 777 light years away from the Sun. While the star bears the Bayer designation Chi Persei, it is not to be confused with the entire cluster NGC 884, commonly referred to as Chi Persei. It is faintly visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.99. This object is moving closer to the Earth with a heliocentric radial velocity of −12.5 km/s.

This is an evolved giant star with a stellar classification of G7 III, most likely (93% chance) on the horizontal branch. At the age of 191 million years, it has 3.84 times the mass of the Sun but has expanded to 24 times the Sun's radius. The star is radiating 316 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,974 K.