20 Vulpeculae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 12m 00.70176s[1] |
| Declination | +26° 28′ 43.6989″[1] |
| Apparent magnitude (V) | 5.91[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B7 Ve[4][5] |
| B−V color index | −0.107±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | −22.0±4.3[2] km/s |
| Proper motion (μ) | RA: +4.096[1] mas/yr Dec.: −9.524[1] mas/yr |
| Parallax (π) | 2.7904 ± 0.0726 mas[1] |
| Distance | 1,170 ± 30 ly (358 ± 9 pc) |
| Absolute magnitude (MV) | −2.13[2] |
| Details | |
| Mass | 4.02±0.14[3] M☉ |
| Radius | 3.0[6] R☉ |
| Luminosity | 460+88 −74[3] L☉ |
| Surface gravity (log g) | 2.90[7] cgs |
| Temperature | 12,050+168 −165[3] K |
| Rotational velocity (v sin i) | 236[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
20 Vulpeculae is single[5] star located around 1,170[1] light years away in the northern constellation of Vulpecula.[8] It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.91.[2] The object is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.[2]
This is a Be star with a stellar classification of B7 Ve.[4] It is spinning rapidly with a projected rotational velocity of 236 km/s (compared to a critical velocity of 332 km/s)[3] and has an estimated polar inclination of 71.1°.[9] The star has four times the mass of the Sun and is radiating around 460 times the Sun's luminosity from its photosphere at an effective temperature of 12,050 K.[3]
References
[edit]- ^ a b c d e f 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.
- ^ a b c d e f 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.
- ^ a b c d e f g Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Antoniou, A.; et al. (2011), "Studying the UV mg II Resonance Lines in 20 Be Stars", Baltic Astronomy, 20 (4): 572–575, Bibcode:2011BaltA..20..572A, doi:10.1515/astro-2017-0338.
- ^ a b Eggleton, P. P.; Tokovinin, A. A. (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.
- ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ Chauville, J.; et al. (November 2001), "High and intermediate-resolution spectroscopy of Be stars 4481 lines" (PDF), Astronomy and Astrophysics, 378: 861–882, Bibcode:2001A&A...378..861C, doi:10.1051/0004-6361:20011202.
- ^ a b "20 Vulpeculae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-16.
- ^ Frémat, Y.; Zorec, J.; Hubert, A.-M.; Floquet, M. (2005), "Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars", Astronomy and Astrophysics, 440 (1): 305, arXiv:astro-ph/0503381, Bibcode:2005A&A...440..305F, doi:10.1051/0004-6361:20042229, S2CID 19016751.
External links
[edit]- 20 Vulpeculae on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
