Astronomy:31 Pegasi
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 22h 21m 31.07511s[1] |
| Declination | 12° 12′ 18.6628″[1] |
| Apparent magnitude (V) | 4.85 - 5.05[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B2IV-Ve[4] |
| U−B color index | -0.81[5] |
| B−V color index | -0.10[5] |
| Variable type | γ Cas[2] |
| Astrometry | |
| Radial velocity (Rv) | −5.30[6] km/s |
| Proper motion (μ) | RA: +6.32[1] mas/yr Dec.: +4.80[1] mas/yr |
| Parallax (π) | 2.01 ± 0.28[1] mas |
| Distance | approx. 1,600 ly (approx. 500 pc) |
| Absolute magnitude (MV) | −3.61[7] |
| Details | |
| Mass | 12.5±0.7[3] M☉ |
| Radius | 11.6[8] R☉ |
| Luminosity (bolometric) | 27,925+4,360 −3,770[3] L☉ |
| Surface gravity (log g) | 3.71±0.15[3] cgs |
| Temperature | 23,890±740[3] K |
| Rotational velocity (v sin i) | 98±8[3] km/s |
| Age | 15.4±1.3[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
31 Pegasi is a single[11] star in the northern constellation of Pegasus. It is visible to the naked eye as a dim, blue-white hued point of light with an apparent visual magnitude of about 5. It is located approximately 1,600 light years away from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −5.3 km/s.[6]
This is a massive Be star with a stellar classification of B2IV-V.[13] It is a 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.[2] It is spinning with a projected rotational velocity of 98 km/s, with the pole being inclined by an estimated angle of 26°±9° to the line of sight from the Earth.[3] The star is 15.4[9] million years old with 12.5[3] times the mass of the Sun. It is radiating around 28,000 times the luminosity of the Sun from its photosphere at an effective temperature of 23,890 K.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 2.0 2.1 2.2 Samus, N. N. et al. (2009). "General Catalogue of Variable Stars". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Zorec, J. et al. (2016). "Critical study of the distribution of rotational velocities of Be stars". Astronomy & Astrophysics 595: A132. doi:10.1051/0004-6361/201628760. Bibcode: 2016A&A...595A.132Z.
- ↑ 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. Bibcode: 1995yCat.5050....0H.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ Arcos, C.; Kanaan, S.; Chávez, J.; Vanzi, L.; Araya, I.; Curé, M. (2018). "Stellar parameters and H α line profile variability of be stars in the BeSOS survey". Monthly Notices of the Royal Astronomical Society 474 (4): 5287. doi:10.1093/mnras/stx3075. Bibcode: 2018MNRAS.474.5287A.
- ↑ 9.0 9.1 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. doi:10.1111/j.1365-2966.2010.17434.x. Bibcode: 2011MNRAS.410..190T. Vizier catalog entry
- ↑ "31 Peg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=31+Peg.
- ↑ 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access.
- ↑ Lesh, Janet Rountree (December 1968). "The Kinematics of the Gould Belt: an Expanding Group?". Astrophysical Journal Supplement 17: 371. doi:10.1086/190179. Bibcode: 1968ApJS...17..371L.
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