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 or ε Cassiopeiae, officially named Segin (/ˈsɛɡɪn/), is a single star in the northern constellation of Cassiopeia. 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.