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

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ a b "20 Vulpeculae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-16.
  9. ^ 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.
Allikas: https://en.wikipedia.org/wiki/20_Vulpeculae
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