Zeta Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 17h 08m 47.19596s |
| Declination | +65° 42′ 52.8634″ |
| Apparent magnitude (V) | +3.17 |
| Characteristics | |
| Spectral type | B6 III |
| U−B color index | −0.43 |
| B−V color index | −0.11 |
| Astrometry | |
| Radial velocity (Rv) | −17 km/s |
| Proper motion (μ) | RA: –20.43 mas/yr Dec.: +19.61 mas/yr |
| Parallax (π) | 9.93±0.35 mas |
| Distance | 330 ± 10 ly (101 ± 4 pc) |
| Absolute magnitude (MV) | −1.88 |
| Details | |
| A | |
| Mass | 5.940±1.134 M☉ |
| Radius | 6.19±0.49 R☉ |
| Luminosity | 883 L☉ |
| Surface gravity (log g) | 4.24 cgs |
| Temperature | 15,000±800 K |
| Metallicity [Fe/H] | −0.95 dex |
| Rotational velocity (v sin i) | 55 km/s |
| B | |
| Mass | 3.645±0.770 M☉ |
| Other designations | |
| 22 Draconis, BD+65 1170, FK5 639, HD 155763, HIP 83895, HR 6396, SAO 17365, WDS 17088+6543 | |
| Database references | |
| SIMBAD | data |
Zeta Draconis (ζ Draconis, abbreviated Zet Dra, ζ Dra) is a binary star in the northern circumpolar constellation of Draco. With an apparent visual magnitude of +3.17, it is the fifth-brightest member of this generally faint constellation. Its distance from the Sun has been measured using the parallax technique, yielding an estimate of roughly 330 light-years (100 parsecs).
The two components are designated Zeta Draconis A (formally named Aldhibah /ælˈdaɪbə/, after the traditional name of the system) and B.