Kappa Pegasi

Kappa Pegasi

Observation data Epoch J2000      Equinox J2000
Constellation	Pegasus
Right ascension	21^h 44^m 38.7344^s[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)	28.90 ± 0.18 mas[3]
Distance	112.9 ± 0.7 ly (34.6 ± 0.2 pc)
Orbit[3]
Primary	κ Peg A
Companion	κ Peg B
Period (P)	4227.05 ± 0.55 d
Semi-major axis (a)	8.139 ± 0.062 AU
Eccentricity (e)	0.3180 ± 0.0015
Inclination (i)	107.872 ± 0.028°
Longitude of the node (Ω)	109.140 ± 0.057°
Periastron epoch (T)	2452398.0 ± 2.0
Argument of periastron (ω) (secondary)	304.14 ± 0.21°
Orbit[3]
Primary	κ Peg Ba
Companion	κ Peg Ba
Period (P)	5.9714971 ± 0.0000013
Semi-major axis (a)	0.08715 ± 0.00090 AU
Eccentricity (e)	0.0073 ± 0.0013
Inclination (i)	124.9 ± 3.7°
Longitude of the node (Ω)	359.1 ± 5.9°
Periastron epoch (T)	2452402.225 ± 0.097
Argument of periastron (ω) (secondary)	359.1 ± 5.9°
Details
Mass	1.549/1.662/0.814[3] M☉
Surface gravity (log g)	3.00[4] cgs
Temperature	6,579[4] K
Metallicity [Fe/H]	-0.37 dex
Rotational velocity (v sin i)	35[5] km/s
Other designations
10 Pegasi, HR 8315, BD+24 4463, HD 206901, SAO 89949, HIP 107354.[6]
Database references
SIMBAD	data

Kappa Pegasi (κ Peg, κ 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. No proper name is associated to this star.^[7]

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

1. Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics. 323: L49 – L52. Bibcode:1997A&A...323L..49P.
2. 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): 99. Bibcode:1966CoLPL...4...99J.
3. 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. S2CID 18533602.
4. 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): 1. Bibcode:1970CoAsi.239....1B.
6. "kap Peg -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-05-25.
7. Kaler, Jim. "Kappa Pegasi". Archived from the original on 2016-11-04. Retrieved 2016-08-02.