Sigma Persei

σ Persei

Location of σ Persei (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Perseus
Right ascension	03h 30m 34.48545s[1]
Declination	47° 59′ 42.7808″[1]
Apparent magnitude (V)	4.36[2]
Characteristics
Spectral type	K3III[3]
U−B color index	+1.54[2]
B−V color index	+1.35[2]
Astrometry
Radial velocity (Rv)	+14.36[4] km/s
Proper motion (μ)	RA: +3.56[1] mas/yr Dec.: +18.48[1] mas/yr
Parallax (π)	9.07 ± 0.26 mas[1]
Distance	360 ± 10 ly (110 ± 3 pc)
Absolute magnitude (MV)	-0.85[5]
Details
Mass	1.32[6] M☉
Radius	36.89[6] R☉
Luminosity	368[6] L☉
Surface gravity (log g)	1.46[6] cgs
Temperature	4,165[6] K
Metallicity [Fe/H]	-0.20[6] dex
Rotational velocity (v sin i)	< 1.0[7] km/s
Other designations
σ Persei, σ Per, Sigma Per, 35 Persei, BD+47°843, FK5 124, GC 4158, HD 21552, HIP 16335, HR 1052, NSV 1167, PPM 46257, SAO 38890
Database references
SIMBAD	data

Sigma Persei (Sigma Per, σ Persei, σ Per) is an orange K-type giant^[3] with an apparent magnitude of +4.36.^[2] It is approximately 360 light years from Earth.^[1]

Sigma Persei is moving through the Galaxy at a speed of 17.4 km/s relative to the Sun. Its projected Galactic orbit carries it between 24,400 and 43,600 light years from the center of the Galaxy. It came closest to the Sun 5.1 million years ago when it had brightened to magnitude 3.11 from a distance of 202 light years.^[8]

It has one reported planet, b, with a period of 580 days and a mass approximately 6.5 times that of Jupiter.^[9]

This star, together with δ Per, ψ Per, α Per, γ Per and η Per, has been called the Segment of Perseus.^[10]