Gamma Pegasi
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 00h 13m 14.15123s |
| Declination | +15° 11′ 00.9368″ |
| Apparent magnitude (V) | +2.78 to 2.89 |
| Characteristics | |
| Spectral type | B2 IV |
| U−B color index | −0.85 |
| B−V color index | −0.23 |
| Variable type | β Cep |
| Astrometry | |
| Radial velocity (Rv) | +4.1 km/s |
| Proper motion (μ) | RA: +1.98 mas/yr Dec.: –9.28 mas/yr |
| Parallax (π) | 6.9474±0.4293 mas |
| Distance | 470 ± 30 ly (144 ± 9 pc) |
| Absolute magnitude (MV) | −2.51±0.15 |
| Details | |
| A | |
| Mass | 8.8±0.3 M☉ |
| Radius | 5.4±0.4 R☉ |
| Luminosity | 6,000+900 −800 L☉ |
| Surface gravity (log g) | 3.95±0.05 cgs |
| Temperature | 22,000±400 K |
| Metallicity [Fe/H] | −0.34 dex |
| Rotational velocity (v sin i) | 8 km/s |
| Age | 21.9+1.0 −1.4 Myr |
| Other designations | |
| Algenib, γ Pegasi, 88 Pegasi, FK5 7, HD 886, HIP 1067, HR 39, SAO 91781 | |
| Database references | |
| SIMBAD | data |
Gamma Pegasi is a binary star in the constellation of Pegasus, located at the southeast corner of the asterism known as the Great Square. It has the formal name Algenib /ælˈdʒiːnɪb/; the Bayer designation Gamma Pegasi is Latinized from γ Pegasi and abbreviated Gamma Peg or γ Peg. The average apparent visual magnitude of +2.84 makes this the fourth-brightest star in the constellation. The distance to this system has been measured using the parallax technique, yielding a value of roughly 470 light-years (144 parsecs).