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 |