Astronomy:8 Cygni
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Short description: Star in the constellation Cygnus
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 31m 46.32184s[1] |
| Declination | +34° 27′ 10.6874″[1] |
| Apparent magnitude (V) | 4.75[2] |
| Characteristics | |
| Spectral type | B3 IV[3] |
| B−V color index | −0.155[2] |
| Astrometry | |
| Radial velocity (Rv) | −21.20±0.1[4] km/s |
| Proper motion (μ) | RA: 1.16[1] mas/yr Dec.: −3.47[1] mas/yr |
| Parallax (π) | 3.79 ± 0.16[1] mas |
| Distance | 860 ± 40 ly (260 ± 10 pc) |
| Details | |
| Mass | 6.40[5] M☉ |
| Radius | 6.50[5] R☉ |
| Luminosity | 2,512[5] L☉ |
| Surface gravity (log g) | 3.62[5] cgs |
| Temperature | 16,100[5] K |
| Metallicity [Fe/H] | +0.25[5] dex |
| Rotational velocity (v sin i) | 15[6] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
8 Cygni is a single[7] star in the northern constellation of Cygnus. Based upon its parallax of 3.79 mas,[1] it is approximately 860 light-years (260 parsecs) away from Earth. It is visible to the naked eye as a faint, bluish-white hued star with an apparent visual magnitude of about 4.7.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[4]
This is an aging subgiant star, as indicated by its spectral type of B3IV.[3] Its effective temperature of 16,100 K fits into the normal range of B-type stars: 11,000 to 25,000 K. 8 Cygni is about twice as hot as the Sun, and it is six times larger and many times brighter in comparison.[5] The elemental abundances are near solar.[8]
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. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL.
- ↑ 2.0 2.1 2.2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode: 1986EgUBV........0M. http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1.
- ↑ 3.0 3.1 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
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Challouf, M. et al. (2014), "Improving the surface brightness-color relation for early-type stars using optical interferometry⋆", Astronomy & Astrophysics 570: A104, doi:10.1051/0004-6361/201423772, Bibcode: 2014A&A...570A.104C.
- ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal 573 (1): 359–365. doi:10.1086/340590. Bibcode: 2002ApJ...573..359A.
- ↑ 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.
- ↑ Adelman, Saul J. (June 1998). "Elemental abundance analyses with DAO spectrograms - XIX. The superficially normal B stars zeta Draconis, epsilon Lyrae, 8 Cygni and 22 Cygni". Monthly Notices of the Royal Astronomical Society 296 (4): 856–862. doi:10.1046/j.1365-8711.1998.01426.x. Bibcode: 1998MNRAS.296..856A.
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