Kappa Pegasi
Triple star system in the constellation Pegasus
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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.[8]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 21h 44m 38.7344s[1] |
| Declination | +25° 38â² 42.128â³[1] |
| Apparent magnitude (V) | 4.159 |
| Characteristics | |
| Spectral type | F5IV |
| UâB color index | +0.03[2] |
| BâV color index | +0.44[2] |
| Astrometry | |
| Radial velocity (Rv) | â8.1 km/s |
| Proper motion (μ) | RA: 46.66[1] mas/yr Dec.: 13.47[1] mas/yr |
| Parallax (Ï) | 28.90±0.18 mas[3] |
| Distance | 112.9 ± 0.7 ly (34.6 ± 0.2 pc) |
| Orbit[3] | |
| Primary | κ Peg A |
| Name | 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 (Ï) (secondary) | 304.14 ± 0.21° |
| Orbit[3] | |
| Primary | κ Peg Ba |
| Name | κ Peg Bb |
| 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 (Ï) (secondary) | 359.1 ± 5.9° |
| Details[4] | |
| A | |
| Mass | 1.391±0.044 Mâ |
| Surface gravity (log g) | 3.00[5] cgs |
| Temperature | 6,579[5] K |
| Metallicity [Fe/H] | -0.37 dex |
| Rotational velocity (v sin i) | 35[6] km/s |
| Ba | |
| Mass | 1.616±0.049 Mâ |
| Bb | |
| Mass | 0.835±0.026 Mâ |
| Other designations | |
| 10 Pegasi, HR 8315, BD+24 4463, HD 206901, SAO 89949, HIP 107354.[7] | |
| 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]
