Kappa Pegasi

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Kappa Pegasi
Observation data
Epoch J2000      Equinox J2000
Constellation Pegasus
Right ascension 21h 44m 38.7344s[1]
Declination +25° 38′ 42.128″[1]
Apparent magnitude (V) 4.159
Characteristics
Spectral type F5IV
U−B color index +0.03[2]
B−V color index +0.44[2]
Astrometry
Radial velocity (Rv) −8.1 km/s
Proper motion (μ) RA: 46.66[1] mas/yr
Dec.: 13.47[1] mas/yr
Parallax (π) 28.34 ± 0.88[1] mas
Distance 115 ± 4 ly
(35 ± 1 pc)
Details
Mass 1.55/1.66/0.81[3] M
Surface gravity (log g) 3.00[4] cgs
Temperature 6,579[4] K
Metallicity \begin{smallmatrix}\left[\frac{Fe}{H}\right]\ =\ -0.37\end{smallmatrix}[4]
Rotational velocity (v sin i) 35[5] km/s
Other designations
HR 8315, BD+24 4463, HD 206901, SAO 89949, HIP 107354.[6]

Kappa Pegasi is a triple star system in the constellation Pegasus. It has an apparent brightness of +4.13 magnitude and belongs to the spectral class F5IV; a subgiant star.

This system consists of two components, designated Kappa Pegasi A and B, that are separated by an angular distance of 0.235 arcseconds. The binary nature of this pair was discovered by Sherburne W. Burnham in 1880. They orbit around each other every 11.6 years with a semimajor axis of 0.4 arcseconds. The brighter member of the pair, Kappa Pegasi B, is actually a spectroscopic binary, with the components designated Kappa Pegasi Ba and Kappa Pegasi Bb. They orbit about each other every six days. There is a fourth component, Kappa Pegasi C, which may be an optical companion.[3]

References[edit]

  1. ^ a b c d e Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics 323: L49–L52. Bibcode:1997A&A...323L..49P. 
  2. ^ a b Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory 4 (99). Bibcode:1966CoLPL...4...99J. 
  3. ^ a b Muterspaugh, Matthew W.; et al. (January 2006). "PHASES Differential Astrometry and Iodine Cell Radial Velocities of the κ Pegasi Triple Star System". The Astrophysical Journal 636 (2): 1020–1032. arXiv:astro-ph/0509406. Bibcode:2006ApJ...636.1020M. doi:10.1086/498209. 
  4. ^ a b c Balachandran, Suchitra (May 1, 1990). "Lithium depletion and rotation in main-sequence stars". Astrophysical Journal, Part 1 354: 310–332. Bibcode:1990ApJ...354..310B. doi:10.1086/168691. 
  5. ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago 239 (1). Bibcode:1970CoAsi.239....1B. 
  6. ^ "kap Peg -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-05-25.