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) | 33.0268 ± 0.1631 mas [5] |
Distance | 98.8 ± 0.5
ly (30.3 ± 0.1 pc) |
Absolute magnitude (MV) | 2.7 [6] |
Orbit [6] | |
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° |
Details [7] | |
κ Del Aa | |
Mass | 1.43 M☉ |
Luminosity | 8.3 L☉ |
Surface gravity (log g) | 3.69 cgs |
Temperature | 5,643 K |
Metallicity [Fe/H] | +0.01 dex |
Rotational velocity (v sin i) | 1.77 km/s |
Age | 3.1 Gyr |
κ Del Ab | |
Mass | 0.4±0.2 [6] M☉ |
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 98.8 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. [6] The secondary star is a low-mass star, at only 0.4 M☉. [6]
A third star is 12th magnitude ADS 14101 B, 10 ″ away in 2001, but it is a background object. HD 196794 is an 8th magnitude K2 subgiant 214″ away is at the same distance as κ Delphini and shares a common proper motion. [6]