Kappa Delphini
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 39m 07.78430s[1] |
| Declination | +10° 05′ 10.3383″[1] |
| Apparent magnitude (V) | 5.05[2] |
| Characteristics | |
| Spectral type | G1IV + ? + K2IV[3] |
| U−B color index | 0.235[4] |
| B−V color index | 0.69[4] |
| Astrometry | |
| Radial velocity (Rv) | -53.51[2] km/s |
| Proper motion (μ) | RA: 323.83[1] mas/yr Dec.: 21.80[1] mas/yr |
| Parallax (π) | 33.20 ± 0.28[1] mas |
| Distance | 98.2 ± 0.8 ly (30.1 ± 0.3 pc) |
| Absolute magnitude (MV) | 2.7[5] |
| Orbit[5] | |
| Period (P) | 45 ± 5 yr |
| Semi-major axis (a) | 0.520 ± 0.030″ |
| Eccentricity (e) | 0.8 ± 0.4 |
| Inclination (i) | 107 ± 18° |
| Longitude of the node (Ω) | 326 ± 17° |
| Periastron epoch (T) | B 1971.2 ± 1.8 |
| Argument of periastron (ω) (secondary) | 8 ± 34° |
| Other designations | |
| Database references | |
| SIMBAD | data |
κ Delphini (Latinised as Kappa Delphini, abbreviated to κ Del or kappa Del) is a binary star system in the constellation Delphinus. It is faintly visible to the naked eye, with an apparent magnitude of 5.05.[2] It is located about 98.2 light-years away, based on its parallax.[1]
Kappa Delphini is an astrometric binary. The primary star is an early G-type subgiant star. It has a mass 1.61 times that of the Sun, and is 6.8 times more luminous. The companion star regularly perturbs the G-type primary star primary, causing it to wobble around the barycenter. From this, an orbital period of 45 years has been calculated.[5] The secondary star is a low-mass star, at only 0.4 M☉.[5] A third star, designated ADS 14101 B, is a K-type subgiant, and may be physically associated.[5]
References
- 1 2 3 4 5 6 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
- 1 2 3 4 "* kap Del". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 26 December 2016.
- ↑ Eggl, S.; Pilat-Lohinger, E.; Funk, B.; Georgakarakos, N.; Haghighipour, N. (2012). "Circumstellar habitable zones of binary-star systems in the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 428 (4): 3104. arXiv:1210.5411. Bibcode:2013MNRAS.428.3104E. doi:10.1093/mnras/sts257.
- 1 2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Bibcode:1986EgUBV........0M.
- 1 2 3 4 5 Gontcharov, G.A.; Kiyaeva, O.V. (2010). "Photocentric orbits from a direct combination of ground-based astrometry with Hipparcos II. Preliminary orbits for six astrometric binaries". New Astronomy. 15 (3): 324. arXiv:1606.08182. Bibcode:2010NewA...15..324G. doi:10.1016/j.newast.2009.09.006.