Chi Draconis

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Chi Draconis A/B
Observation data
Epoch J2000
Constellation
(pronunciation)		 Draco
Right ascension 18h 21m 03.4s
Declination +72° 43′ 58″
Apparent magnitude (V) 3.68 / 5.67
Characteristics
Spectral type F7 Vvar / K0 V
U-B color index -0.06
B-V color index 0.49
Variable type Suspected
Astrometry
Radial velocity (Rv) +32.0 km/s
Proper motion (μ) RA: 531.08 mas/yr
Dec.: -351.59 mas/yr
Parallax (π) 124.11 ± 0.48 mas
Distance 26.3 ± 0.1 ly
(8.06 ± 0.03 pc)
Absolute magnitude (MV) 4.16
Visual binary orbit
Companion Chi Draconis B
Period (P) 0.768 yr
Semimajor axis (a) 0.124"
Eccentricity (e) 0.414
Inclination (i) 74.8°
Longitude of the node (Ω) ?°
Periastron epoch (T) ?
Details
Mass 1.03/0.75 M☉
Radius 1.2/0.75 R☉
Luminosity 1.86/0.29 L☉
Temperature 6,100/4,900 K
Metallicity 47/47%
Rotation 11 km/s.
Age 8 × 109 years
Other designations
Batenateban Borealis, 44 Dra, Gl 713, HR 6927, BD +72°839, HD 170153, LHS 3379, LTT 15438, GCTP 4245.00, SAO 9087, FK5 695, LFT 1413, WDS 18211+7244A, NSV 10749, IRAS 18220+7242, HIP 89937.

Chi Draconis (χ Dra) is a star system in the constellation Draco. This star has been called by the traditional name of Batentaban Borealis, derived from the Arabic بطن الثعبان baţn al-thubān, meaning the Dragon's (or Serpent's) Belly.

The first companion is a yellow-white (class F) fourth-magnitude star with a mass approximately equal to that of the sun, but it is nearly twice as luminous. The second companion is an orange (class K) sixth-magnitude star, that is less massive and of lesser luminosity than the sun. In 1898 this system was reported to be a spectroscopic binary system, with an orbital period of 280.55 days. The two stars have an average separation of nearly an astronomical unit, which would disrupt the orbit of any Earth-like planet that was close enough to the primary to support liquid water. The two stars have about half the abundance of heavy elements as the Sun, but are approximately twice as old.

[edit] In Fiction

See Chi Draconis in fiction.

[edit] References

  • D. N. Monin, S. N. Fabrika, G. G. Valyavin, 2000, "Magnetic survey of bright northern main sequence stars", A&A 396, 131-141.

[edit] External links