Omicron Pegasi
ο Pegasi, Latinized as Omicron Pegasi, is a suspected astrometric binary[7] 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 J2000.0 Equinox J2000.0 | |
|---|---|
| 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[1] mas |
| Distance | 290 ± 10 ly (88 ± 3 pc) |
| Absolute magnitude (MV) | −0.01[3] |
| Details | |
| Mass | 2.24[5] M☉ |
| Luminosity | 104.24[2] L☉ |
| Surface gravity (log g) | 3.77±0.14[5] cgs |
| Temperature | 9,956±338[5] K |
| Metallicity [Fe/H] | 0.0[3] dex |
| Rotational velocity (v sin i) | 6.0±0.2[3] km/s |
| Age | 184[5] Myr |
| Other designations | |
| 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 104[2] times the Sun's luminosity from its photosphere at an effective temperature of 9,956 K.[5]
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015
- Gray, David F. (April 2014). "Precise Rotation Rates for Five Slowly Rotating a Stars". The Astronomical Journal. 147 (4): 13. Bibcode:2014AJ....147...81G. doi:10.1088/0004-6256/147/4/81. 81.
- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146.
- "omi Peg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-10-10.
- Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.