17h34m 59.59363s[1]
+61° 52′ 28.4006″[1]
5.236[2]
Characteristics
G0Va (F9V + K3V)[3]
U−B color index
+0.100[2]
B−V color index
+0.595[2]
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)
46.3 ± 0.2 ly
(14.19 ± 0.07 pc)
Absolute magnitude (MV)
4.58±0.011[5]
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°
151°
Periastron epoch (T)
1947
Argument of periastron (ω)
(secondary)
307°
Details
Surface gravity (log g)
Metallicity [Fe/H]
Rotational velocity (v sin i)
10[10] km/s
Database references
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]
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]
The Gliese 685 planetary system
Companion
(in order from star)
9.0+1.7−1.8 M🜨
0.1344
24.160+0.061−0.047 d
—
—
—
The space velocity components of 26 Draconis are U = +36.5, V = −4.3 and W = −21.8 km/s.[15] This system is on an orbit through the Milky Way galaxy that has an eccentricity of 0.14, taking it as close as 23.1 kly (7.08 kpc) and as far as 30.4 kly (9.32 kpc) from the galactic core. The inclination of this orbit carries the star system as much as 0.75 kly (0.23 kpc) above the plane of the galactic disk.[16] This system may be a member of the Ursa Major moving group.[17]
Other
Other