13 Comae Berenices

13 Comae Berenices is a probable binary star^[3] system in the northern constellation of Coma Berenices. It has an apparent visual magnitude of 5.17,^[2] which is bright enough to be faintly visible to the naked eye. With an annual parallax shift of 12.33 mas,^[1] it is located around 260 light years from the Sun. It is member of the nearby Coma Star Cluster (Melotte 111).^[7]

13 Comae Berenices

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Coma Berenices
Right ascension	12h 24m 18.52125s[1]
Declination	+26° 05′ 55.0346″[1]
Apparent magnitude (V)	5.17[2]
Characteristics
Spectral type	A3 V[3][2]
B−V color index	0.082±0.003[2]
Astrometry
Radial velocity (Rv)	+0.1±0.1[4] km/s
Proper motion (μ)	RA: −28.29[1] mas/yr Dec.: +3.07[1] mas/yr
Parallax (π)	12.33±1.11 mas[1]
Distance	260 ± 20 ly (81 ± 7 pc)
Absolute magnitude (MV)	0.38[2]
Details
Mass	2.83[5] M☉
Luminosity	60.93[2] L☉
Surface gravity (log g)	3.84±0.14[5] cgs
Temperature	8,846±301[5] K
Metallicity [Fe/H]	0.24[2] dex
Rotational velocity (v sin i)	48[5] km/s
Age	429[5] Myr
Other designations
13 Com, GN Com, BD+26° 2344, HD 107966, HIP 60514, HR 4717, SAO 82291[6]
Database references
SIMBAD	data

Based on measured changes in the star's motion, this is most likely an astrometric binary system.^[3] The visible component is an A-type main-sequence star with a stellar classification of A3 V.^[3] In 1965, Gerhard Jackisch discovered the star is a variable star.^[8] It was given its variable star designation, GN Comae Berenices, in 1975.^[9] It is catalogued as an Alpha² Canum Venaticorum variable.^[10] Rensom (1990) listed it as a suspected Am star.^[11] The system is a source of X-ray emission, which may be coming from the companion.^[12]