Omicron Pegasi
Star in the constellation Pegasus
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ο Pegasi, Latinized as Omicron Pegasi, is a suspected astrometric binary[8] star system in the northern constellation of Pegasus. It is white in hue and visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.80.[2] The distance to this system is approximately 290 light years based on parallax,[1] and it is drifting further away from the Sun with a radial velocity of +8.5 km/s.[2]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 22h 41m 45.39893s[1] |
| Declination | +29° 18′ 27.5542″[1] |
| Apparent magnitude (V) | +4.80[2] |
| Characteristics | |
| Spectral type | A1 IV[3] |
| U−B color index | +0.035[4] |
| B−V color index | −0.013±0.002[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.5±0.1[2] km/s |
| Proper motion (μ) | RA: −0.106[1] mas/yr Dec.: −31.691[1] mas/yr |
| Parallax (π) | 11.4116±0.4055 mas[1] |
| Distance | 290 ± 10 ly (88 ± 3 pc) |
| Absolute magnitude (MV) | −0.01[3] |
| Details | |
| Mass | 2.24[5] M☉ |
| Radius | 3.37±0.10[6] R☉ |
| Luminosity | 85±6[6] L☉ |
| Surface gravity (log g) | 3.81±0.04[6] cgs |
| Temperature | 9,600±50[6] K |
| Metallicity [Fe/H] | +0.25±0.09[6] dex |
| Rotational velocity (v sin i) | 6.0±0.2[3] km/s |
| Age | 184[5] Myr |
| Other designations | |
| ο Peg, 43 Pegasi, BD+28°4436, HD 214994, HIP 112051, HR 8641, SAO 90717[7] | |
| Database references | |
| SIMBAD | data |
The visible component has a stellar classification of A1 IV,[3] matching a subgiant star that has begun to cool, expand and brighten off the main sequence. It has very narrow lines due to a low projected rotational velocity of 6 km/s. The abundances of iron are Sun-like, while it displays an overabundance of heavier elements. Some studies have suggested it is an Am-like star.[3] Omicron Pegasi is an estimated 184 million years old with 2.24 times the mass of the Sun.[5] It is radiating 85 times the Sun's luminosity from its photosphere at an effective temperature of 9,600 K.[6]