39 Draconis
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Draco |
| Right ascension | 18h 23m 54.60641s |
| Declination | +58° 48′ 02.6446″ |
| Apparent magnitude (V) | 5.034 (5.06 + 8.07) |
| Characteristics | |
| Spectral type | A1V + F5V |
| U−B color index | +0.06 |
| B−V color index | +0.10 |
| Astrometry | |
| Radial velocity (Rv) | -24.53 ± 0.23 km/s |
| Proper motion (μ) |
RA: -37.82 mas/yr Dec.: 61.60 mas/yr |
| Parallax (π) | 17.71 ± 0.35mas |
| Distance | 184 ± 4 ly (56 ± 1 pc) |
| Absolute magnitude (MV) | 1.31 / 4.32 |
| Orbit | |
| Period (P) | 3962.50 ± 209.26 yr |
| Semi-major axis (a) | 6.621 ± 0.325″ |
| Eccentricity (e) | 0.553 ± 0.005 |
| Inclination (i) | 107.7 ± 0.12° |
| Longitude of the node (Ω) | 179.9 ± 0.10° |
| Periastron epoch (T) | 5671.40 ± 12.08 |
|
Argument of periastron (ω) (secondary) |
128.0 ± 2.18° |
| Details | |
| 39 Dra A | |
| Mass | 2.12 M☉ |
| Radius | 2.3 R☉ |
| Surface gravity (log g) | 4.05 ± 0.07 cgs |
| Temperature | 8710 K |
| 39 Dra B | |
| Mass | 1.18 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | 39 Dra |
| 39 Dra A | |
| 39 Dra B | |
39 Draconis, also known as b Draconis, is a wide binary star in the constellation Draco. Its apparent magnitude is 5.034. Parallax measurements made by the Hipparcos spacecraft put it at a distance of 184 light-years, or 56 parsecs away.
The two components of 39 Draconis are separated by 6.621″ and take almost 4,000 years to orbit each other. The primary star is an early A-type main-sequence star, 2.12 times the mass of the Sun. The secondary star is an F-type main-sequence star, and is 1.18 times the mass of the Sun.
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