Star in the constellation Pegasus
31 Pegasi Location of 31 Pegasi (circled)
Observation dataEpoch J2000 Equinox J2000 Constellation Pegasus Right ascension 22h 21m 31.07511s [ 1] Declination 12° 12′ 18.6628″[ 1] Apparent magnitude (V)4.99[ 2] Characteristics Spectral type B2IV-Ve[ 3] U−Bcolor index -0.81[ 2] B−Vcolor index -0.10[ 2] Variable type γ Cas Astrometry Radial velocity (Rv )−5.30[ 4] km/s Proper motion (μ)RA: +6.32[ 1] mas /yr Dec.: +4.80[ 1] mas /yr Parallax (π)2.01± 0.28 mas [ 1] Distance approx. 1,600 ly pc ) Absolute magnitude (MV )−3.61[ 5] Details[ 6] Mass ± 0.7M ☉ Luminosity (bolometric) +4,360 L ☉ Surface gravity (log g )± 0.15cgs Temperature ± 740K Rotational velocity (v sin i )± 8Age ± 1.3[ 7] Myr Other designations 31 Peg ,IN Peg ,BD +11°4784FK5 843GC 31255HD 212076HIP 110386HR 8520SAO 107854[ 8] Database references SIMBAD data
31 Pegasi is a single[ 9] star in the northernconstellation ofPegasus . It is visible to the naked eye as a dim, blue-white hued point of light with a baselineapparent visual magnitude of 4.99.[ 2] light years away from the Sun based on parallax,[ 1] radial velocity of −5.3 km/s.[ 4]
Alight curve for IN Pegasi, plotted fromHipparcos [ 10] This is amassive Be star with astellar classification of B2IV-V.[ 11] γ Cas variable ; a type of shell star with a circumstellar disc of gas surrounding the star at the equator, and ranges from 5.05 up to 4.85 in visual magnitude.[ 12] projected rotational velocity of 98 km/s, with the pole being inclined by an estimated angle of± 9°[ 6] [ 7] [ 6] mass of the Sun . It is radiating around 28,000 times theluminosity of the Sun from itsphotosphere at aneffective temperature of 23,890 K.[ 6]
^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 . ^ Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue".VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H .5050 (5th Revised ed.).Bibcode :1995yCat.5050....0H . ^a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system".Astronomy Letters .32 (11):759– 771.arXiv :1606.08053 Bibcode :2006AstL...32..759G .doi :10.1134/S1063773706110065 .S2CID 119231169 . ^ 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 c d Zorec, J.; et al. (2016)."Critical study of the distribution of rotational velocities of Be stars" .Astronomy & Astrophysics .595 : A132.Bibcode :2016A&A...595A.132Z .doi :10.1051/0004-6361/201628760 hdl :11336/37946 ^a b Tetzlaff, N.; et al. (2011)."A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun" .Monthly Notices of the Royal Astronomical Society .410 (1):190– 200.arXiv :1007.4883 Bibcode :2011MNRAS.410..190T .doi :10.1111/j.1365-2966.2010.17434.x S2CID 118629873 . Vizier catalog entry ^ "31 Peg" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2019-07-01 .^ 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 . ^ "Hipparcos Tools Interactive Data Access" .Hipparcos . ESA. Retrieved8 December 2021 .^ Lesh, Janet Rountree (December 1968)."The Kinematics of the Gould Belt: an Expanding Group?" .Astrophysical Journal Supplement .17 : 371.Bibcode :1968ApJS...17..371L .doi :10.1086/190179 ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "General Catalogue of Variable Stars".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S .1 .Bibcode :2009yCat....102025S .
