Xi Pegasi

Xi Pegasi (ξ Peg, ξ Pegasi) is the Bayer designation for a double star in the northern constellation of Pegasus, the winged horse. Located in the horse's neck, the primary component is an F-type main sequence star that is visible to the naked eye with an apparent visual magnitude of 4.2.^[2] It is 86% larger and 17% more massive that the Sun, radiating 4.5 times the solar luminosity.^[8] Based upon parallax measurements taken with the Hipparcos spacecraft, it is located 53.2 ± 0.2 light years from the Sun.^[1]

Xi Pegasi

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Pegasus
Right ascension	22h 46m 41.58118s[1]
Declination	+12° 10′ 22.3854″[1]
Apparent magnitude (V)	4.195[2] + 11.70[3]
Characteristics
Spectral type	F6V[4] + M3.5[5]
U−B color index	−0.015[2]
B−V color index	+0.502[2]
Astrometry
Radial velocity (Rv)	−5.3[6] km/s
Proper motion (μ)	RA: +234.18[1] mas/yr Dec.: −493.29[1] mas/yr
Parallax (π)	61.36 ± 0.19 mas[1]
Distance	53.2 ± 0.2 ly (16.30 ± 0.05 pc)
Absolute magnitude (MV)	3.25[7]
Details
Xi Peg A
Mass	1.17[8] M☉
Radius	1.86[8] R☉
Luminosity	4.5[8] L☉
Surface gravity (log g)	3.97±0.07[8] cgs
Temperature	6,178±26[8] K
Metallicity [Fe/H]	−0.27±0.03[8] dex
Rotational velocity (v sin i)	12.67[9] km/s
Age	5.0±0.5[8] Gyr
Xi Peg B
Mass	0.32[10] M☉
Temperature	3,569[3] K
Metallicity [Fe/H]	−0.25[3] dex
Other designations
46 Peg, Gl 872, BD+11° 4875, HD 215648, HIP 112447, HR 8665, SAO 108165.[11]
Database references
SIMBAD	data

The primary has been examined for the presence of an infrared excess that might indicate the presence of a debris disk, but none has been discovered.^[12] The common proper motion companion, NLTT 54820, is a twelfth magnitude red dwarf located at an angular separation of 11.4″ along a position angle of 96.9°.^[13] This corresponds to a projected physical separation of 192.3 AU.^[12]

References

1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series, 61: 387–405, Bibcode:1985A&AS...61..387K.
3. Rojas-Ayala, Bárbara; et al. (April 2012), "Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs", The Astrophysical Journal, 748 (2): 93, arXiv:1112.4567, Bibcode:2012ApJ...748...93R, doi:10.1088/0004-637X/748/2/93, S2CID 41902340.
4. Gray, R. O.; Graham, P. W.; Hoyt, S. R. (April 2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. II. Basic Parameters of Program Stars and the Role of Microturbulence", The Astronomical Journal, 121 (4): 2159–2172, Bibcode:2001AJ....121.2159G, doi:10.1086/319957, S2CID 250878890.
5. Bidelman, W. P. (October 1985), "G. P. Kuiper's spectral classifications of proper-motion stars", Astrophysical Journal Supplement Series, 59: 197–227, Bibcode:1985ApJS...59..197B, doi:10.1086/191069.
6. Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W.
7. Huang, W.; et al. (2012), "A catalogue of Paschen-line profiles in standard stars", Astronomy & Astrophysics, 547: A62, arXiv:1210.7893, Bibcode:2012A&A...547A..62H, doi:10.1051/0004-6361/201219804, S2CID 119286159.
8. Ghezzi, L.; et al. (September 2010), "Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity", The Astrophysical Journal, 720 (2): 1290–1302, arXiv:1007.2681, Bibcode:2010ApJ...720.1290G, doi:10.1088/0004-637X/720/2/1290, S2CID 118565025.
9. Martínez-Arnáiz, R.; et al. (September 2010), "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter" (PDF), Astronomy and Astrophysics, 520: A79, arXiv:1002.4391, Bibcode:2010A&A...520A..79M, doi:10.1051/0004-6361/200913725, S2CID 43455849, archived from the original (PDF) on 2017-09-22, retrieved 2018-11-04.
10. Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, S2CID 56066740, 87.
11. "ksi Peg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-12-10.
12. Moro-Martín, A.; et al. (March 2015), "Does the Presence of Planets Affect the Frequency and Properties of Extrasolar Kuiper Belts? Results from the Herschel Debris and Dunes Surveys", The Astrophysical Journal, 801 (2): 28, arXiv:1501.03813, Bibcode:2015ApJ...801..143M, doi:10.1088/0004-637X/801/2/143, S2CID 55170390, 143.
13. Gould, Andrew; Chanamé, Julio (February 2004), "New Hipparcos-based Parallaxes for 424 Faint Stars", The Astrophysical Journal Supplement Series, 150 (2): 455–464, arXiv:astro-ph/0309001, Bibcode:2004ApJS..150..455G, doi:10.1086/381147, S2CID 8494577.

External links

• Kaler, James B., "Xi Pegasi", Stars, University of Illinois, retrieved 2016-01-07.