Kappa Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 12h 33m 28.94206s |
| Declination | +69° 47′ 17.6331″ |
| Apparent magnitude (V) | 3.82 |
| Characteristics | |
| Spectral type | B6 IIIe |
| U−B color index | −0.61 |
| B−V color index | −0.11 |
| Astrometry | |
| Radial velocity (Rv) | −11.4 km/s |
| Proper motion (μ) | RA: −58.162 mas/yr Dec.: +11.802 mas/yr |
| Parallax (π) | 7.1387±0.3291 mas |
| Distance | 460 ± 20 ly (140 ± 6 pc) |
| Absolute magnitude (MV) | −1.95 + 2.4 |
| Orbit | |
| Period (P) | 61.5496 ± 0.0058 d |
| Semi-major axis (a) | 0.487 ± 0.021 au |
| Eccentricity (e) | 0 |
| Inclination (i) | 130.0 ± 3.4° |
| Longitude of the node (Ω) | 118.0 ± 1.3° |
| Semi-amplitude (K1) (primary) | 6.90±0.15 km/s |
| Details | |
| κ Dra A | |
| Mass | 3.65 ± 0.48 M☉ |
| Radius | 5.85 ± 0.18 R☉ |
| Luminosity | 1178 ± 151 L☉ |
| Surface gravity (log g) | 3.5 cgs |
| Temperature | 13982 ± 392 K |
| Metallicity [Fe/H] | −0.65 dex |
| Rotational velocity (v sin i) | 200 ± 12 km/s |
| κ Dra B | |
| Mass | 0.426 ± 0.043 M☉ |
| Radius | 0.69 ± 0.07 R☉ |
| Luminosity | 33 ± 17 L☉ |
| Temperature | 16700 ± 2000 K |
| Rotational velocity (v sin i) | 35 ± 10 km/s |
| Other designations | |
| κ Dra, 5 Dra, BD+70°703, FK5 472, HD 109387, HIP 61281, HR 4787, SAO 7593 | |
| Database references | |
| SIMBAD | data |
Kappa Draconis, Latinized from κ Draconis, is a blue giant star located in the northern circumpolar constellation of Draco. At an apparent magnitude of 3.88, it is barely visible to the naked eye when artificial lighting from cities is present. Nevertheless, it is a powerful star, approximately five time as massive as the Sun. It is about 460 light-years away, and is 1,400 times brighter than the Sun.
The star is currently located at declination +69° 47′ 18″ (right ascension 12h 33m 29.0s), but due to the effects of precession, Kappa Draconis was the nearest star to the north celestial pole visible to the naked eye from 1793 BC to approximately 1000 BC, though it was 6° removed from perfect alignment, making it only an approximate pole star, similar to the roughly 7° variance from perfect alignment of the much brighter (magnitude 2.08) star Kochab, at the same time during Earth's precession.