Rho2 Cephei

For other stars with this Bayer designation, see ρ Cephei.

Rho² Cephei, Latinized from ρ² Cephei, or simply ρ Cephei, is a solitary^[9] star in the northern constellation of Cepheus. With an apparent visual magnitude of 5.50,^[2] it is faintly visible to the naked eye, forming an optical pair with Rho¹ Cephei. Based upon an annual parallax shift of 13.31 mas as seen from the Earth,^[1] it is located about 245 light years from the Sun.

Rho² Cephei

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Cepheus
Right ascension	22h 29m 52.97918s[1]
Declination	+78° 49′ 27.4282″[1]
Apparent magnitude (V)	5.50[2]
Characteristics
Spectral type	A3 V[3]
U−B color index	+0.07[2]
B−V color index	+0.06[2]
Astrometry
Proper motion (μ)	RA: +3.68[1] mas/yr Dec.: −21.29[1] mas/yr
Parallax (π)	13.31±0.21 mas[1]
Distance	245 ± 4 ly (75 ± 1 pc)
Absolute magnitude (MV)	+1.07[4]
Details
Mass	2.23±0.03[5] M☉
Luminosity	32[4] L☉
Surface gravity (log g)	4.2[6] cgs
Temperature	8,511[5] K
Rotational velocity (v sin i)	133[7] km/s
Age	85[6] Myr
Other designations
Cephei, ρ2 Cep, 29 Cephei, BD+78°801, FK5 1593, HD 213798, HIP 111056, HR 8591, SAO 10402[8]
Database references
SIMBAD	data

Rho² Cephei is an A-type main sequence star with a stellar classification of A3 V,^[3] estimated to be 85 million years old. It has a high rate of rotation, showing a projected rotational velocity of 133 km/s.^[7] The effective temperature of its photosphere is 8,511 K and its bolometric luminosity, the total amount of radiation it emits at all wavelengths, is 32 L_☉.