Kappa Pegasi
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]
| 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) | 28.90 ± 0.18[3] mas |
| 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 | |
| Database references | |
| SIMBAD | data |
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
- Perryman, M. A. C.; et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
- 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.
- 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.
- 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.
- 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.
- "kap Peg -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-05-25.
- Kaler, Jim. "Kappa Pegasi". Archived from the original on 2016-11-04. Retrieved 2016-08-02.