Epsilon Cassiopeiae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 01h 54m 23.73409s |
| Declination | +63° 40′ 12.3602″ |
| Apparent magnitude (V) | 3.37 |
| Characteristics | |
| Spectral type | B3 V |
| U−B color index | −0.62 |
| B−V color index | −0.15 |
| Variable type | Periodic |
| Astrometry | |
| Radial velocity (Rv) | −8.1 km/s |
| Proper motion (μ) | RA: +29.587 mas/yr Dec.: −18.387 mas/yr |
| Parallax (π) | 7.0037±0.1599 mas |
| Distance | 470 ± 10 ly (143 ± 3 pc) |
| Absolute magnitude (MV) | −2.19 |
| Details | |
| Mass | 9.2±0.2 M☉ |
| Radius | 6.10±0.06 R☉ |
| Luminosity | 3,059 L☉ |
| Surface gravity (log g) | 3.5 cgs |
| Temperature | 15,174 K |
| Metallicity [Fe/H] | −0.28 dex |
| Rotational velocity (v sin i) | 30 km/s |
| Age | 15.4±3.0 Myr |
| Other designations | |
| Segin, Epsilon Cas, ε Cas, 45 Cassiopeiae, BD+62 320, FK5 63, HD 11415, HIP 8886, HR 542, SAO 12031 | |
| Database references | |
| SIMBAD | data |
Epsilon Cassiopeiae is a single star in the northern constellation of Cassiopeia. It has the proper name Segin, pronounced /ˈsɛɡɪn/; Epsilon Cassiopeiae is the Bayer designation, which is Latinized from ε Cassiopeiae and abbreviated Epsilon Cas or ε Cas. With an apparent visual magnitude of 3.4, this is one of the brightest stars in the constellation. The distance to this star has been determined directly using parallax measurements, yielding a value of around 460–430 light-years (140–130 parsecs) from the Sun. It is drifting closer with a radial velocity of −8 km/s.