8 Cygni

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8 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 31m 46.32184s[1]
Declination +34° 27′ 10.6874″[1]
Apparent magnitude (V) 4.75[2]
Characteristics
Spectral type B3IV
U−B color index −0.66
B−V color index −0.155[2]
Astrometry
Radial velocity (Rv) −21.20 ± 0.1[3] 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[4] M
Radius 6.50[4] R
Luminosity 2,512[4] L
Surface gravity (log g) 3.62[4] cgs
Temperature 16,100[4] K
Metallicity [Fe/H] +0.25[4] dex
Rotational velocity (v sin i) 15[5] km/s
Other designations
8 Cygni, BD+34° 3590, HD 184171, HIP 96052, HR 7426, SAO 68447.
Database references
SIMBAD data

8 Cygni is a 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. Its apparent magnitude is about 4.7,[2] making it faintly visible to the naked eye.

8 Cygni is a bluish-white subgiant star, as indicated by its spectral type of B3IV. Therefore, its surface 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 that of the Sun, and it is larger and many times brighter in comparison.[4]

References[edit]

  1. ^ a b c d e f van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. Bibcode:2007A&A...474..653V. arXiv:0708.1752Freely accessible. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M. 
  3. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. Bibcode:2006AstL...32..759G. arXiv:1606.08053Freely accessible. doi:10.1134/S1063773706110065. Retrieved 12 December 2016. 
  4. ^ a b c d e f g Challouf, M.; et al. (2014), "Improving the surface brightness-color relation for early-type stars using optical interferometry⋆", Astronomy & Astrophysics, 570: A104, Bibcode:2014A&A...570A.104C, arXiv:1409.1351Freely accessible, doi:10.1051/0004-6361/201423772. 
  5. ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573: 359. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.