AR Cephei
Variable star in the constellation Cepheus
From Wikipedia, the free encyclopedia
AR Cephei (AR Cep) is a variable star in the constellation Cepheus. It is classified as a semiregular star[7][8] with a spectral type of M4III.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 51m 33.86137s[1] |
| Declination | +85° 02′ 46.9418″[1] |
| Apparent magnitude (V) | 6.9 - 8.3[2] |
| Characteristics | |
| Spectral type | M4 III[3] |
| B−V color index | +1.52[4] |
| Variable type | SRb[2] |
| Astrometry | |
| Radial velocity (Rv) | −15.66±0.23[1] km/s |
| Proper motion (μ) | RA: 26.580[1] mas/yr Dec.: 4.143[1] mas/yr |
| Parallax (π) | 3.2317±0.0967 mas[1] |
| Distance | 1,010 ± 30 ly (309 ± 9 pc) |
| Details | |
| Mass | 2.8[5] M☉ |
| Radius | 123[1] R☉ |
| Luminosity | 2,094[1] L☉ |
| Surface gravity (log g) | 1.49[5] cgs |
| Temperature | 2,400 - 3,700[citation needed] K |
| Metallicity [Fe/H] | −0.39[5] dex |
| Other designations | |
| BD+84 516, HD 217158, HIP 112882, SAO 3809[6] | |
| Database references | |
| SIMBAD | data |
Aernout de Sitter discovered the star in 1933.[3][9] It was given its variable star designation, AR Cephei, in 1939.[9]
AR Cephei is located approximately 1,010 light-years (309 parsecs) from the Solar System, and has a radial velocity of -16 km/s, meaning that it is moving toward the Sun at ~16 kilometers every second.[1]