Kappa Cephei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 20h 08m 53.34492s |
| Declination | +77° 42′ 41.0909″ |
| Apparent magnitude (V) | 4.39 |
| Characteristics | |
| Spectral type | B9III + A7V |
| U−B color index | -0.11 |
| B−V color index | -0.05 |
| Astrometry | |
| Absolute magnitude (MV) | −0.54 |
| Kap Cep A | |
| Radial velocity (Rv) | −22.8±0.9 km/s |
| Proper motion (μ) | RA: +12.044 mas/yr Dec.: +26.199 mas/yr |
| Parallax (π) | 10.0861±0.2468 mas |
| Distance | 323 ± 8 ly (99 ± 2 pc) |
| Kap Cep B | |
| Radial velocity (Rv) | −15.3±5 km/s |
| Proper motion (μ) | RA: +10.725±0.047 mas/yr Dec.: +25.543±0.056 mas/yr |
| Parallax (π) | 9.9981±0.0290 mas |
| Distance | 326.2 ± 0.9 ly (100.0 ± 0.3 pc) |
| Details | |
| Kap Cep A | |
| Mass | 3.02±0.5 M☉ |
| Radius | 4.45±0.22 R☉ |
| Luminosity | 191 L☉ |
| Surface gravity (log g) | 3.66±0.03 cgs |
| Temperature | 10,174±55 K |
| Metallicity [Fe/H] | −0.05 dex |
| Age | 302+77 −72 Myr |
| Kap Cep B | |
| Radius | 1.32 R☉ |
| Luminosity | 4.05 L☉ |
| Temperature | 7119 K |
| Other designations | |
| κ Cep, 1 Cephei, BD+77°764, HD 192907, HIP 99255, HR 7750, SAO 9665, GSC 04589-03106 | |
| Database references | |
| SIMBAD | data |
| B | |
| C | |
Kappa Cephei, Latinized from κ Cephei, is a binary star system in the northern circumpolar constellation of Cepheus. It is visible to the naked eye as a faint, blue white-hued point of light with an apparent visual magnitude is 4.39. The system is located approximately 323–326 light years distant from the Sun, based on parallax.
The two gravitationally-bound members of this system had an angular separation of 7.3″ along a position angle of 120°, as of 2015. The primary, designated component A, has a stellar classification of B9III, matching a blue giant. The magnitude 8.34 secondary, component B, is an A-type main-sequence star of class A7V. A third star of 10th magnitude, BD+77 763, is listed as component C in the Washington Double Star Catalog although it is a background object unrelated to the other two.