Omega Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 17h 36m 57.09431s |
| Declination | +68° 45′ 28.6815″ |
| Apparent magnitude (V) | 4.80 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | F5V |
| U−B color index | −0.01 |
| B−V color index | +0.43 |
| Astrometry | |
| Radial velocity (Rv) | −13.98±0.02 km/s |
| Proper motion (μ) | RA: +1.690 mas/yr Dec.: +321.452 mas/yr |
| Parallax (π) | 42.0939±0.1425 mas |
| Distance | 77.5 ± 0.3 ly (23.76 ± 0.08 pc) |
| Absolute magnitude (MV) | 2.95 |
| Orbit | |
| Period (P) | 5.2797766±0.0000044 d |
| Semi-major axis (a) | 3.469±0.017 mas |
| Eccentricity (e) | 0.00220±0.00031 |
| Inclination (i) | 151.4±1.1° |
| Longitude of the node (Ω) | 1.23±0.32° |
| Periastron epoch (T) | JD 2454349.083±0.083 |
| Argument of periastron (ω) (secondary) | 314.8±5.6° |
| Semi-amplitude (K1) (primary) | 36.254±0.016 km/s |
| Semi-amplitude (K2) (secondary) | 44.720±0.016 km/s |
| Details | |
| ω Dra A | |
| Mass | 1.46±0.16 M☉ |
| Luminosity | 5.61 L☉ |
| Temperature | 6,500 K |
| Metallicity [Fe/H] | 0.18±0.05 dex |
| Age | 1.9 Gyr |
| ω Dra B | |
| Mass | 1.18±0.13 M☉ |
| Temperature | 5,900 K |
| Metallicity [Fe/H] | 0.0 dex |
| Other designations | |
| ω Dra, 28 Dra, BD+68°949, GJ 4017, HD 160922, HIP 86201, HR 6596, SAO 17576 | |
| Database references | |
| SIMBAD | data |
Omega Draconis, Latinized from ω Draconis and also known as 28 Draconis, is a binary star in the constellation of Draco. The system is fairly close, and is located about 78 light-years (24 parsecs) away, based on its parallax.
Omega Draconis is a spectroscopic binary, which means the two stellar components are too close to be resolved but periodic Doppler shifts in their spectra indicate orbital motion. In this case, light from both stars can be detected, and it is a double-lined spectroscopic binary. The orbital period of the system is 5.28 days, and the eccentricity of the system is 0.00220, implying a nearly circular orbit. The primary has a mass of 1.46 M☉, and is an F-type main-sequence star. The secondary is less massive, at 1.18 M☉.