Chi Pegasi
Red giant star in the constellation Pegasus
Chi Pegasi , Latinised from χ Pegasi, is a single[11] star in the northern constellation of Pegasus , along the eastern constellation border with Pisces . It has a reddish hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.80.[2] The distance to this star is approximately 368 light-years based on parallax ,[1] but it is drifting closer with a radial velocity of −46 km/s.[6]
A light curve for Chi Pegasi, plotted from Hipparcos data[12]
This is an aging red giant star on the asymptotic giant branch [3] with a stellar classification of M2+III.[4] It is about 8 billion years old with a mass 6% greater than the Sun's . With the supply of hydrogen at its core exhausted, the star has cooled and expanded to 53 times the girth of the Sun . It is radiating around 435 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,842 K .[8]
Chi Pegasi is a suspected small-amplitude variable .[5] Koen and Eyer examined the Hipparcos data for Chi Pegasi, and found that its brightness varied by 0.0094 magnitudes, with a period of 5.9641 days.[13]
References
^ a b c d e f 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 . Vizier catalog entry
^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues . 2237 . Bibcode :2002yCat.2237....0D .
^ a b Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal . 104 (1): 275–313. Bibcode :1992AJ....104..275E . doi :10.1086/116239 .
^ a b Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series . 71 : 245. Bibcode :1989ApJS...71..245K . doi :10.1086/191373 . S2CID 123149047 .
^ a b Percy, John R.; Wong, Nancy; Bohme, Dietmar; Curott, David R.; Dempsey, Frank; Fortier, George L.; Ganis, Matt; Parello, Stephanie; Landis, Howard J.; Luedeke, Kenneth D.; Pray, Donald; Smith, Michael S.; Snyder, Leroy F.; Thompson, Raymond R.; Wasson, Rick; Williams, Harold O.; Walker, William S. G.; Wood, James E. (June 1994). "Photometric Surveys of Suspected Small-Amplitude Red Variables. III. an AAVSO Photoelectric Photometry Survey" . Publications of the Astronomical Society of the Pacific . 106 : 611. Bibcode :1994PASP..106..611P . doi :10.1086/133420 .
^ a b c Massarotti, Alessandro; et al. (January 2008). "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity" . The Astronomical Journal . 135 (1): 209–231. Bibcode :2008AJ....135..209M . doi :10.1088/0004-6256/135/1/209 .
^ 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 . Vizier catalog entry
^ a b Baines, Ellyn K.; et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer" . The Astronomical Journal . 155 (1). 30. arXiv :1712.08109 . Bibcode :2018AJ....155...30B . doi :10.3847/1538-3881/aa9d8b . S2CID 119427037 .
^ 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 .
^ "chi Peg" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved January 12, 2011 .
^ 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 .
^ "Light Curve" . Hipparcos ESA . ESA. Retrieved 10 October 2022 .
^ Koen, Chris; Eyer, Laurent (March 2002). "New periodic variables from the Hipparcos epoch photometry" . Monthly Notices of the Royal Astronomical Society . 331 (1): 45–59. arXiv :astro-ph/0112194 . Bibcode :2002MNRAS.331...45K . doi :10.1046/j.1365-8711.2002.05150.x .
External links