Mu Persei, Latinised from μ Persei, is a binary star system in the northern constellation of Perseus. It is visible to the naked eye as a point of light with a combined apparent visual magnitude of +4.16.[2] The distance to this system is approximately 900 light-years based on parallax measurements.[1] It is drifting further away with a radial velocity of +26 km/s.[6]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Perseus |
Right ascension | 04h 14m 53.86253s[1] |
Declination | +48° 24′ 33.5912″[1] |
Apparent magnitude (V) | +4.16[2] |
Characteristics | |
Spectral type | G0Ib[3] + B9.5[4] |
B−V color index | 0.935±0.002[5] |
Astrometry | |
Radial velocity (Rv) | 26.46[6] km/s |
Proper motion (μ) | RA: 5.52[1] mas/yr Dec.: −17.37[1] mas/yr |
Parallax (π) | 3.62 ± 0.20 mas[1] |
Distance | 900 ± 50 ly (280 ± 20 pc) |
Absolute magnitude (MV) | −3.08[5] |
Orbit[7] | |
Period (P) | 284 d |
Semi-major axis (a) | 18.8 ± 8.8 mas |
Eccentricity (e) | 0.062 |
Inclination (i) | 74 ± 24° |
Longitude of the node (Ω) | 296 ± 18° |
Periastron epoch (T) | 2,420,062 |
Argument of periastron (ω) (secondary) | 302° |
Details | |
Radius | ~53[8] R☉ |
Luminosity | ~2030[8] L☉ |
Surface gravity (log g) | 1.74[9] cgs |
Temperature | 5418[9] K |
Metallicity [Fe/H] | 0.09[9] dex |
Rotational velocity (v sin i) | 12[10] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Mu Persei is a spectroscopic binary with an orbital period of 284 days and an eccentricity of about 0.06.[7] The primary component is a yellow G-type supergiant star. With an effective temperature of about 5,400 K and a radius of 53 solar radii, this star has the luminosity of about 2,030 times that of the Sun.[8] The companion is a B-type star with a class of B9.5[4]
Mu Persei is moving through the galaxy at a speed of 35.6 km/s relative to the Sun. Its projected galactic orbit carries it between 23,900 and 32,400 light-years from the center of the galaxy.[12]
Mu Persei came closest to the Sun 5.6 million years ago when it had brightened to magnitude 3.25 from a distance of 600 light-years.[12]
In Chinese, 天船 (Tiān Chuán), meaning Celestial Boat, refers to an asterism consisting of μ Persei, η Persei, γ Persei, α Persei, ψ Persei, δ Persei, 48 Persei and HD 27084. Consequently, μ Persei itself is known as 天船七 (Tiān Chuán qī, English: the Seventh Star of Celestial Boat).[13]