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 mas [1] |
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]
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 |
---|---|---|---|---|---|---|
b | 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]
70 Ophiuchi is a binary star system located 16.6 light years away from the Earth. It is in the constellation Ophiuchus. At magnitude 4 it appears as a dim star visible to the unaided eye away from city lights.
Xi Boötis, Latinised from ξ Boötis, is a binary star system located at a distance of 22 light-years away from Earth. It is the nearest visible star in the constellation Boötes. The brighter, primary component of the pair has a visual magnitude of 4.70, making it visible to the naked eye.
Zeta Trianguli Australis is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.
Nu Draconis is a double star in the constellation Draco. The respective components are designated ν1 Draconis and ν2 Draconis. The second component is a spectroscopic binary star system.
Alpha Caeli is a double star system in the constellation Caelum.
Chi Draconis is a star system in the constellation Draco. It also has the Flamsteed designation 44 Draconis.
Upsilon2 Centauri is a binary star system in the southern constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude of +4.33. Based upon an annual parallax shift of just 2.57 mas as seen from Earth, this star is located roughly 1,300 light years from the Sun. Relative to its neighbors, the system has a peculiar velocity of 39.2+8.8
−15.2 km/s and it may form a runaway star system.
Tau Librae, Latinized from τ Librae, is the Bayer designation for a binary star system at the southern edge of the zodiac constellation of Libra. It can be seen with the naked eye, having an apparent visual magnitude of 3.68. The distance to this system is around 367 light years, as determined from an annual parallax shift of 8.89 mas.
HD 224635 and HD 224636 is a pair of stars comprising a binary star system in the constellation Andromeda. They are located approximately 94 light years away and they orbit each other every 717 years.
HD 225218 is a quadruple star system in the northern constellation of Andromeda. The primary component, HD 225218 A, is a giant star with a stellar classification of B9III, an apparent magnitude of 6.16, and is a candidate Lambda Boötis star. It has a fainter, magnitude 9.65 companion, HD 225218 B, at an angular separation of 5.2″ along a position angle of 171°. The primary itself has been identified as a binary star system through interferometry, with the two components separated by 0.165″. The pair, HD 225218 Aa and Ab, orbit each other with a period of about 70 years and an eccentricity of 0.515. Component B is likewise a spectroscopic binary.
HD 6114 is a visual binary star system in the northern constellation of Andromeda. With a combined apparent magnitude of 6.46, the star can only be seen with the naked eye by keen-eyed observers even on the best of nights. Based upon an annual parallax shift of 10.4 mas as seen from Earth's orbit, the system is located approximately 108 parsecs (350 ly) distant.
V538 Aurigae is a single star in the northern constellation of Auriga. With an apparent visual magnitude of 6.23, this star requires good dark sky conditions to view with the naked eye. It is located at a distance of 40.0 light-years (12.3 pc) from Sun based on parallax. The star is drifting further away with a radial velocity of 0.9 km/s. It is a member of the Local Association, and is most likely a thin disk star.
SZ Crateris is a binary star system in the southern constellation Crater. Both components belong to the main sequence: the primary star has a spectral classification of K5V while the secondary is a red dwarf of spectral class M0V. The radius of the primary is about 66% the radius of the Sun, while the secondary member is only about 42% of the solar radius. In 1994, the two stars were separated by 5.1 arc seconds, which is equivalent to 112.41 astronomical units.
Theta Draconis, a name Latinized from θ Draconis, is a binary star system in the northern circumpolar constellation of Draco. It is faintly visible to the naked eye at night with an apparent visual magnitude of 4.12. Parallax measurements place it at an estimated distance of 68.6 light-years from the Sun, and it is drifting closer with a radial velocity of −8 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.464″ per year. O. J. Eggen included this star as a member of the NGC 1901 supercluster based on its space motion.
Gliese 282 is a star system composed of four stars in the equatorial constellation of Monoceros. At a distance of 36 light years, this star has an apparent magnitude of 7.26 when viewed from Earth. It is not visible to the naked eye.
HR 7955 is a binary star system in the northern circumpolar constellation of Cepheus, near the constellation border with Cygnus. It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.51. The system is located at a distance of 89 light-years from the Sun, based on parallax. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.243 arc seconds per annum, and is drifting closer to the Sun with a radial velocity of -33 km/s.
39 Draconis is a wide binary star system in the northern circumpolar constellation of Draco. It has the Bayer designation b Draconis, while 39 Draconis is the Flamsteed designation. This system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.0. Parallax measurements made by the Hipparcos spacecraft put it at a distance of 184 light-years, or 56 parsecs away from the Sun. The system is moving closer to the Earth with a heliocentric radial velocity of -24.5 km/s.
Pi5 Orionis (π5 Ori, π5 Orionis) is a binary star system in the constellation Orion. It has an apparent visual magnitude of 3.69, which is bright enough to be visible to the naked eye on a clear night. Based upon an annual parallax shift of 2.43 mas, it is around 1,300 light-years distant from the Sun.
Kappa Fornacis is a star system that lies approximately 72 light-years away. The system consists of a somewhat evolved primary orbited by a massive, 'dark' secondary that is actually itself a close red dwarf binary, making a hierarchal triple system.
ADS 7251 is a binary star system 6.33 parsecs from the Sun. The components are near-identical red dwarfs separated by 17″ in 2019.