Chi Draconis

Chi Draconis (χ Dra, χ Draconis, Chi Draconis) is a star system in the constellation Draco.

χ Draconis
Location of χ Draconis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Draco
Right ascension  18h 21m 03.38255s[1]
Declination +72° 43′ 58.2518″[1]
Apparent magnitude (V) 3.570[2] (3.68 / 5.67)
Characteristics
Spectral type F7V[3] / K0V
U−B color index -0.06
B−V color index 0.49
Variable type Suspected
Astrometry
Radial velocity (Rv)+32.4[2] km/s
Proper motion (μ) RA: 531.21[1] mas/yr
Dec.: -349.71[1] mas/yr
Parallax (π)124.11 ± 0.87[1] mas
Distance26.3 ± 0.2 ly
(8.06 ± 0.06 pc)
Absolute magnitude (MV)4.04[2]
Orbit[4]
CompanionChi Draconis B
Period (P)0.7680599 ± 0.000061 yr
Semi-major axis (a)0.1244 ± 0.0011″
Eccentricity (e)0.428 ± 0.012
Inclination (i)74.42 ± 0.58°
Longitude of the node (Ω)230.30 ± 0.51°
Periastron epoch (T)1984.8324 ± 0.0026
Argument of periastron (ω)
(secondary)		119.3 ± 1.1°
Details
χ Dra A
Mass1.029 ± 0.026[5] M☉
Radius1.20 ± 0.09[5] R☉
Luminosity1.86[5] L☉
Temperature6,150 ± 150[5] K
Metallicity [Fe/H]−0.41[2] dex
Rotational velocity (v sin i)11[6] km/s
Age5.3[2] Gyr
χ Dra B
Mass0.748 ± 0.017[5] M☉
Radius0.73 ± 0.11[5] R☉
Luminosity0.29[5] L☉
Temperature4,940 ± 200[5] K
Other designations
χ Dra, 44 Dra, BD+72° 839, FK5 695, Gl 713, HD 170153, HIP 89937, HR 6927, LHS 3379, LTT 15438, SAO 9087.[3]
Database references
SIMBADdata

Description
χ Draconis in optical light

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 less than half the abundance of heavy elements as the Sun and are approximately a billion years older.[2] Separations between the two stars have been measured[4][7] and the difference in brightness between the two stars is 2.12 magnitudes at 700 nm[7].

gollark: I don't think that is actually what the legal system thinks.
gollark: In practice the information is available *anyway*, but if someone gets it from a specific place they might be inclined to go "something must be done!!!!!" and blame that.
gollark: No, I mean Discord and the admins of this server would get blamed/sued/whatever.
gollark: Probably not styro, more like... Discord and/or the server's admins?
gollark: I assume it's to avoid being blamed in case some stupid person explodes things.

See also

References
  1. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357
  2. Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics, 418: 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959
  3. "chi Dra -- Star in double system", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-10-15
  4. Farrington, C. D.; et al. (June 2010), "Separated Fringe Packet Observations with the CHARA Array. I. Methods and New Orbits for χ Draconis, HD 184467, and HD 198084", The Astronomical Journal, 139 (6): 2308–2318, Bibcode:2010AJ....139.2308F, doi:10.1088/0004-6256/139/6/2308
  5. Torres, G.; Andersen, J.; Giménez, A., "Accurate masses and radii of normal stars: modern results and applications", The Astronomy and Astrophysics Review, 18 (1–2): 67–126, arXiv:0908.2624, Bibcode:2010A&ARv..18...67T, doi:10.1007/s00159-009-0025-1 See p. 56, entry #15.
  6. Monin, D. N.; Fabrika, S. N.; Valyavin, G. G. (2002). "Magnetic survey of bright northern main sequence stars". Astronomy & Astrophysics. 396 (1): 131–141. Bibcode:2002A&A...396..131M. doi:10.1051/0004-6361:20021425.
  7. Hutter, D. J.; Zavala, R. T.; Tycner, C.; Benson, J. A.; Hummel, C. A.; Sanborn, J.; Franz, O. G.; Johnston, K. J. (9 November 2016). "SURVEYING THE BRIGHT STARS BY OPTICAL INTERFEROMETRY. I. A SEARCH FOR MULTIPLICITY AMONG STARS OF SPECTRAL TYPES F-K". The Astrophysical Journal Supplement Series. 227 (1): 4. arXiv:1609.05254. doi:10.3847/0067-0049/227/1/4.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.