Omicron Pegasi

Omicron Pegasi

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Pegasus
Right ascension	22^h 41^m 45.39893^s[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☉
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
ο Peg, 43 Pegasi, BD+28°4436, HD 214994, HIP 112051, HR 8641, SAO 90717[6]
Database references
SIMBAD	data

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]

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

1. 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.
2. 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, S2CID 119257644
3. 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. S2CID 121928906. 81.
4. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
5. 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. S2CID 33401607.
6. "omi Peg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-10-10.
7. 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, S2CID 14878976.