26 Draconis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 17h 34m 59.59363s[1] |
| Declination | +61° 52′ 28.4006″[1] |
| Apparent magnitude (V) | 5.236[2] |
| Characteristics | |
| Spectral type | G0Va (F9V + K3V)[3] |
| U−B color index | +0.100[2] |
| B−V color index | +0.595[2] |
| Astrometry | |
| Radial velocity (Rv) | –12.7[4] km/s |
| Proper motion (μ) | RA: 277.02[1] mas/yr Dec.: –524.88[1] mas/yr |
| Parallax (π) | 70.47 ± 0.37[1] mas |
| Distance | 46.3 ± 0.2 ly (14.19 ± 0.07 pc) |
| Absolute magnitude (MV) | 4.58±0.011[5] |
| Orbit[6] | |
| Primary | 26 Dra A |
| Companion | 26 Dra B |
| Period (P) | 76.1 yr |
| Semi-major axis (a) | 1.53″ |
| Eccentricity (e) | 0.18 |
| Inclination (i) | 104° |
| Longitude of the node (Ω) | 151° |
| Periastron epoch (T) | 1947 |
| Argument of periastron (ω) (secondary) | 307° |
| Details | |
| Mass | 1.30/0.83[7] M☉ |
| Surface gravity (log g) | 4.50[8] cgs |
| Temperature | 6,000[8] K |
| Metallicity [Fe/H] | -0.18[9] dex |
| Rotational velocity (v sin i) | 10[10] km/s |
| Age | 8.4–11.5[9] Gyr |
| Other designations | |
| AB: 26 Dra, HD 160269, HIP 86036, HR 6573, LHS 3305, LTT 15223, SAO 17546[11] | |
| C: HIP 86037, GJ 685, LTT 15224 | |
| Database references | |
| SIMBAD | AB |
| C | |
26 Draconis is a triple star system[12] in the constellation Draco, located 46 light years from the Sun. Two of the system components, A and B, form a spectroscopic binary that completes an orbit every 76 years. The composite spectral classification of the AB pair is G0V, which decomposes to individual spectral types F9V and K3V.[3] A 1962 study estimated the masses of these two stars as 1.30 and 0.83 times the mass of the Sun, respectively.[7] The stars are considered moderately metal-poor compared to the Sun, which means they have a lower proportion of elements other than hydrogen or helium.[9]
Gliese 685[]
The third component, GJ 685, is a red dwarf spectral classification of M0V. As of 1970, this star is separated by 737.9 arc seconds from the AB pair and they share a common proper motion.[13] The Star GJ 685 has one known planet orbit that was detected by radial velocity. [14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| 9.0+1.7−1.8 M
|