| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 21h 35m 12.8233s [1] |
| Declination | +78° 37′ 28.185″ [1] |
| Apparent magnitude (V) | 6.6 - 12.5 [2] |
| Characteristics | |
| Evolutionary stage | AGB [3] |
| Spectral type | C7,3e [4] |
| Variable type | Mira [2] |
| Astrometry | |
| Proper motion (μ) | RA: 8.278 [1] mas/yr Dec.: 0.748 [1] mas/yr |
| Parallax (π) | 2.0452±0.0697 mas [1] |
| Distance | 1,590 ± 50 ly (490 ± 20 pc) |
| Details | |
| Mass | 5.4 [5] M☉ |
| Radius | 254 [6] R☉ |
| Luminosity | 5,417 [6] L☉ |
| Surface gravity (log g) | 3.61 [5] cgs |
| Temperature | 4,032 [5] K |
| Metallicity [Fe/H] | −0.54 [5] dex |
| Other designations | |
| BD+77°827, HD 206362, HIP 106583, SAO 10100 [7] | |
| Database references | |
| SIMBAD | data |
S Cephei (S Cep), also designated as HD 206362, is a carbon star and Mira-type variable in the constellation Cepheus. Based on the measurement of its annual parallax by the Gaia satellite, the star is approximately ~1,590 ly (~490 pc) away from Earth.
The Gaia satellite shows anomalies in the proper motion of S Cephei compared to its long-term proper motion. These anomalies could indicate the presence of an orbiting companion such as a red dwarf or a brown dwarf. [8]
S Cephei is a carbon star of spectral type C7.3e. [10] It is also a Mira-type variable star whose apparent magnitude varies from 6.6 to 12.5 in the form of a pulsation over a period of 484 days. [2] Its variability was discovered by Karl Hencke in 1858. [11]
