Astronomy:25 Vulpeculae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 22m 03.43076s[1] |
| Declination | +24° 26′ 45.9526″[1] |
| Apparent magnitude (V) | 5.50[2] |
| Characteristics | |
| Spectral type | B6 IVe[3][4] |
| B−V color index | −0.09±0.02[4] |
| Astrometry | |
| Radial velocity (Rv) | −11.0±3.6[5] km/s |
| Proper motion (μ) | RA: +0.605[1] mas/yr Dec.: −5.732[1] mas/yr |
| Parallax (π) | 2.7932 ± 0.1493[1] mas |
| Distance | 1,170 ± 60 ly (360 ± 20 pc) |
| Absolute magnitude (MV) | −1.88[4] |
| Details | |
| Mass | 7±1[6] M☉ |
| Radius | 11±1[6] R☉ |
| Luminosity (bolometric) | 1,345+215 −184[7] L☉ |
| Surface gravity (log g) | 3.52±0.21[7] cgs |
| Temperature | 13,170±330[7] K |
| Rotational velocity (v sin i) | 160±14[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
25 Vulpeculae is a single[2] star in the northern constellation of Vulpecula, located roughly 1,170 light years away from the Sun. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.50[2] This object is moving closer to the Earth with a heliocentric radial velocity of −11 km/s.[5]
This is a Be star with a stellar classification of B6 IVe,[3] matching the spectrum of an aging subgiant with a circumstellar disk of ionized gas. Cowley (1972) had it rated as a more evolved giant star with a class of B8 IIIn,[9] where the 'n' notation indicates "nebulous" lines due to rapid rotation. It has a high rate of spin, showing a projected rotational velocity of 160 km/s.[7] The star has 7 times the mass of the Sun and 11 times the Sun's radius.[6] It is radiating 1,345 times the luminosity of the Sun from its photosphere at an effective temperature of 13,170 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ 3.0 3.1 Slettebak, A. (1982), "Spectral types and rotational velocities of the brighter Be stars and A-F type shell stars", Astrophysical Journal Supplement Series 50: 55–83, doi:10.1086/190820, Bibcode: 1982ApJS...50...55S.
- ↑ 4.0 4.1 4.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 6.0 6.1 6.2 Vieira, R. G. et al. (January 2017), "The life cycles of Be viscous decretion discs: time-dependent modelling of infrared continuum observations", Monthly Notices of the Royal Astronomical Society 464 (3): 3071–3089, doi:10.1093/mnras/stw2542, Bibcode: 2017MNRAS.464.3071V.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Zorec, J. et al. (November 2016), "Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity", Astronomy & Astrophysics 595: 26, doi:10.1051/0004-6361/201628760, Bibcode: 2016A&A...595A.132Z.
- ↑ "25 Vulpeculae". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=25+Vulpeculae.
- ↑ Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal 77: 750–755, doi:10.1086/111348, Bibcode: 1972AJ.....77..750C.
External links
- 25 Vulpeculae on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
Coordinates: 
20h 22m 03.4s, +24° 26′ 46″
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