Phi Persei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Perseus |
| Right ascension | 01h 43m 39.63792s |
| Declination | +50° 41′ 19.4328″ |
| Apparent magnitude (V) | 4.06 (3.96 - 4.11) |
| Characteristics | |
| Spectral type | B2Vep + sdO |
| U−B color index | −0.92 |
| B−V color index | −0.04 |
| Variable type | γ Cas |
| Astrometry | |
| Radial velocity (Rv) | +0.80 km/s |
| Proper motion (μ) | RA: +24.59 mas/yr Dec.: −14.01 mas/yr |
| Parallax (π) | 4.54±0.20 mas |
| Distance | 720 ± 30 ly (220 ± 10 pc) |
| Absolute magnitude (MV) | −3.11 |
| Orbit | |
| Period (P) | 126.6731 days |
| Semi-major axis (a) | 5.89 mas |
| Inclination (i) | 77.6° |
| Longitude of the node (Ω) | 295.7° |
| Periastron epoch (T) | 2456110.03 |
| Semi-amplitude (K1) (primary) | 9.97 km/s |
| Semi-amplitude (K2) (secondary) | 81.3 km/s |
| Details | |
| A | |
| Mass | 9.6 M☉ |
| Radius | 5.5 - 8.0 R☉ |
| Luminosity | 14,454 L☉ |
| Surface gravity (log g) | 4.46 cgs |
| Temperature | 29,300 K |
| Rotational velocity (v sin i) | 440 km/s |
| B | |
| Mass | 1.14 M☉ |
| Radius | 1.3 R☉ |
| Luminosity | 6,310 L☉ |
| Surface gravity (log g) | 4.2 cgs |
| Temperature | 53,000 K |
| Age | 57±9 Myr |
| Other designations | |
| φ Persei, φ Per, Phi Per, 54 Andromedae, BD+49°444, FK5 57, GC 2102, HD 10516, HIP 8068, HR 496, PPM 26670, SAO 22554 | |
| Database references | |
| SIMBAD | data |
Phi Persei (Phi Per, φ Persei, φ Per) is a class B2Vep fourth-magnitude star in the constellation Perseus, location about 720 light-years from Earth.