Kappa Cephei

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Kappa Cephei
Observation data
Epoch J2000      Equinox J2000
Constellation Cepheus
Right ascension 20h 08m 53.348s[1]
Declination +77° 42′ 41.12″[1]
Apparent magnitude (V) 4.395[2]
Characteristics
Spectral type B9III[2] + A7V
U−B color index -0.12
B−V color index -0.04
Astrometry
Radial velocity (Rv) −22.8 ± 0.9[2] km/s
Proper motion (μ) RA: 11.57 ± 0.29[1] mas/yr
Dec.: 24.34 ± 0.33[1] mas/yr
Parallax (π) 10.36 ± 0.29[1] mas
Distance 315 ± 9 ly
(97 ± 3 pc)
Absolute magnitude (MV) -0.53
Details
Radius 4.45 ± 0.22[3] R
Surface gravity (log g) 3.66 ± 0.03[3] cgs
Temperature 10,174 ± 55[3] K
Other designations
kap Cep, 1 Cep, BD+77° 764, GSC 04589-03106, HD 192907, HIP 99255, HR 7750, SAO 9665.

Kappa Cephei (κ Cep) is a binary star[4] in the constellation Cepheus. Its apparent magnitude is 4.395.[2] Located approximately 96.53 parsecs (314.8 ly) distant,[1] the primary is a blue giant of spectral type B9III,[2] a star that has used up its core hydrogen and is likely expanding to become a supergiant. The secondary is a main sequence star of spectral type A7V. It has an apparent magnitude of 8.34 and lies 7.38 arc seconds distant.[5]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. ^ a b c d e "Kappa Cephei". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 12 October 2014. 
  3. ^ a b c Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal 129 (3): 1642–1662, arXiv:astro-ph/0412542, Bibcode:2005AJ....129.1642F, doi:10.1086/427855 
  4. ^ 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. doi:10.1111/j.1365-2966.2008.13596.x.  edit
  5. ^ [1]