# Chi Draconis

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Star in the constellation of 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] Characteristics Spectral type F7V / K0V[3] U−B color index −0.06[4] B−V color index +0.49[4] Variable type Suspected[5] 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) 120.05±0.15 mas[3] Distance 27.17 ± 0.03 ly (8.33 ± 0.01 pc) Absolute magnitude (MV) 4.04[2] Orbit[6] Primary χ Dra Aa Name χ Dra Ab 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) 1,984.8324±0.0026 Argument of periastron (ω) (secondary) 119.3±1.1° Details χ Dra Aa Mass 1.029±0.026[3] M☉ Radius 1.20±0.09[3] R☉ Luminosity 1.86[3] L☉ Temperature 6,150±150[3] K Metallicity [Fe/H] −0.41[2] dex Rotational velocity (v sin i) 11[7] km/s Age 5.3[2] Gyr χ Dra Ab Mass 0.748±0.017[3] M☉ Radius 0.73±0.11[3] R☉ Luminosity 0.29[3] L☉ Temperature 4,940±200[3] K Other designations χ Dra, 44 Dra, NSV 10749, BD+72°839, FK5 695, GJ 713, HD 170153, HIP 89937, HR 6927, SAO 9087, LHS 3379, LTT 15438[8] Database references SIMBAD data

**Chi Draconis** is a [magnitude](/source/Apparent_magnitude) 3.6 [binary star](/source/Binary_star) in the [constellation](/source/Constellation) [Draco](/source/Draco_(constellation)). At a distance of 27 [light-years](/source/Light-year), it is one of the 200 or so [closest stars](/source/List_of_nearest_bright_stars).[9]

## Nomenclature

Chi Draconis ([Latinized](/source/Romanization_of_Greek) from χ Draconis, abbreviated χ Dra, Chi Dra) is the star's [Bayer designation](/source/Bayer_designation). It also has the [Flamsteed designation](/source/Flamsteed_designation) *44 Draconis*.

In a 1971 NASA memorandum, this star was listed with the name *Alahakan*.[10] According to R. H. Allen's *[Star Names](/source/Star_Names)*, *Al ʽAuhaḳān*, meaning "the two black bulls, or ravens", was an Arabic name for χ and [ψ Draconis](/source/Psi_Draconis), among other stars in Draco.[11]

In [Chinese astronomy](/source/Chinese_astronomy), this star is identified as *Yùnǚsì* (御女四), the fourth star of the asterism *Yùnǚ* (御女, Maids-in-waiting; also [31 Leonis](/source/31_Leonis)).[12] Alternatively, it may be *Zhùshǐ* (柱史, Official of Royal Archives),[13] usually identified as [φ Draconis](/source/Phi_Draconis).[12] R. H. Allen (using a now outdated [romanization of Chinese](/source/Romanization_of_Chinese)) said it was *Kwei She*.[11]

## Binary system

χ Draconis in optical light

χ Draconis is a [spectroscopic binary](/source/Spectroscopic_binary) which has been resolved using [speckle interferometry](/source/Speckle_interferometry).[4] The primary is an F7 [main sequence](/source/Main_sequence) star. The spectral type of the companion cannot be determined directly with any accuracy, but is known to be between G8 and K2 and is assumed to be K0. The properties of the secondary suggest that it is also a main-sequence star. The separation of the two stars varies between about 0.05[″](/source/Second_of_arc) and 0.2″ during the [eccentric](/source/Orbital_eccentricity) 182-day orbit.[14]

The primary star has a mass fractionally higher than [the Sun's](/source/Solar_mass), but is significantly larger and hotter resulting in it being 86% more luminous.[3] Its age is estimated to be about five billion years.[2]

The secondary only has about three-quarters the mass of the Sun and is both cooler and smaller. It is only about 29% as luminous.[3] It is calculated to be 2.13 magnitudes fainter than the primary, so it would be of sixth magnitude if visible alone.[15]

## Visual companions

Multiple star catalogues list faint widely separated visible companion stars: a 12th-magnitude star and a 14th-magnitude star about 3[′](/source/Minute_of_arc) from χ Draconis, but only about 10″ from each-other.[16] Both have much smaller parallaxes than χ Draconis and are unrelated background objects.[17]

## See also

- [List of star systems within 25–30 light-years](/source/List_of_star_systems_within_25%E2%80%9330_light-years)

- [List of nearest K-type stars](/source/List_of_nearest_stars_by_spectral_type#List_of_nearest_K-type_stars)

## References

1. ^ [***a***](#cite_ref-aaa474_2_653_1-0) [***b***](#cite_ref-aaa474_2_653_1-1) [***c***](#cite_ref-aaa474_2_653_1-2) [***d***](#cite_ref-aaa474_2_653_1-3) van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". *Astronomy and Astrophysics*. **474** (2): 653–664. [arXiv](/source/ArXiv_(identifier)):[0708.1752](https://arxiv.org/abs/0708.1752). [Bibcode](/source/Bibcode_(identifier)):[2007A&A...474..653V](https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20078357](https://doi.org/10.1051%2F0004-6361%3A20078357). [S2CID](/source/S2CID_(identifier)) [18759600](https://api.semanticscholar.org/CorpusID:18759600).

1. ^ [***a***](#cite_ref-aaa418_989_2-0) [***b***](#cite_ref-aaa418_989_2-1) [***c***](#cite_ref-aaa418_989_2-2) [***d***](#cite_ref-aaa418_989_2-3) [***e***](#cite_ref-aaa418_989_2-4) [***f***](#cite_ref-aaa418_989_2-5) 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](/source/ArXiv_(identifier)):[astro-ph/0405198](https://arxiv.org/abs/astro-ph/0405198). [Bibcode](/source/Bibcode_(identifier)):[2004A&A...418..989N](https://ui.adsabs.harvard.edu/abs/2004A&A...418..989N). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20035959](https://doi.org/10.1051%2F0004-6361%3A20035959). [S2CID](/source/S2CID_(identifier)) [11027621](https://api.semanticscholar.org/CorpusID:11027621).

1. ^ [***a***](#cite_ref-aar18_1_67_3-0) [***b***](#cite_ref-aar18_1_67_3-1) [***c***](#cite_ref-aar18_1_67_3-2) [***d***](#cite_ref-aar18_1_67_3-3) [***e***](#cite_ref-aar18_1_67_3-4) [***f***](#cite_ref-aar18_1_67_3-5) [***g***](#cite_ref-aar18_1_67_3-6) [***h***](#cite_ref-aar18_1_67_3-7) [***i***](#cite_ref-aar18_1_67_3-8) [***j***](#cite_ref-aar18_1_67_3-9) [***k***](#cite_ref-aar18_1_67_3-10) [***l***](#cite_ref-aar18_1_67_3-11) Torres, G.; Andersen, J.; Giménez, A. (2010). "Accurate masses and radii of normal stars: modern results and applications". *The Astronomy and Astrophysics Review*. **18** (1–2): 67–126. [arXiv](/source/ArXiv_(identifier)):[0908.2624](https://arxiv.org/abs/0908.2624). [Bibcode](/source/Bibcode_(identifier)):[2010A&ARv..18...67T](https://ui.adsabs.harvard.edu/abs/2010A&ARv..18...67T). [doi](/source/Doi_(identifier)):[10.1007/s00159-009-0025-1](https://doi.org/10.1007%2Fs00159-009-0025-1). [S2CID](/source/S2CID_(identifier)) [14006009](https://api.semanticscholar.org/CorpusID:14006009). See p. 56, entry #15.

1. ^ [***a***](#cite_ref-bsc_4-0) [***b***](#cite_ref-bsc_4-1) [***c***](#cite_ref-bsc_4-2) Hoffleit, Dorrit; Jaschek, Carlos (1991). "The Bright star catalogue". *New Haven*. [Bibcode](/source/Bibcode_(identifier)):[1991bsc..book.....H](https://ui.adsabs.harvard.edu/abs/1991bsc..book.....H).

1. **[^](#cite_ref-gcvs_5-0)** Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". *VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S*. **1**: B/GCVS. [Bibcode](/source/Bibcode_(identifier)):[2009yCat....102025S](https://ui.adsabs.harvard.edu/abs/2009yCat....102025S).

1. **[^](#cite_ref-aj139_6_2308_6-0)** 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"](https://doi.org/10.1088%2F0004-6256%2F139%2F6%2F2308). *The Astronomical Journal*. **139** (6): 2308–2318. [Bibcode](/source/Bibcode_(identifier)):[2010AJ....139.2308F](https://ui.adsabs.harvard.edu/abs/2010AJ....139.2308F). [doi](/source/Doi_(identifier)):[10.1088/0004-6256/139/6/2308](https://doi.org/10.1088%2F0004-6256%2F139%2F6%2F2308).

1. **[^](#cite_ref-aaa396_1_131_7-0)** Monin, D. N.; Fabrika, S. N.; Valyavin, G. G. (2002). ["Magnetic survey of bright northern main sequence stars"](https://doi.org/10.1051%2F0004-6361%3A20021425). *Astronomy & Astrophysics*. **396** (1): 131–141. [Bibcode](/source/Bibcode_(identifier)):[2002A&A...396..131M](https://ui.adsabs.harvard.edu/abs/2002A&A...396..131M). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20021425](https://doi.org/10.1051%2F0004-6361%3A20021425).

1. **[^](#cite_ref-SIMBAD_8-0)** ["chi Dra -- Star in double system"](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=chi+Dra). *SIMBAD*. [Centre de Données astronomiques de Strasbourg](/source/Centre_de_Donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2011-10-15.

1. **[^](#cite_ref-Reylé2021_9-0)** Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021). "The 10 parsec sample in the Gaia era". *[Astronomy & Astrophysics](/source/Astronomy_%26_Astrophysics)*. **650**: A201. [arXiv](/source/ArXiv_(identifier)):[2104.14972](https://arxiv.org/abs/2104.14972). [Bibcode](/source/Bibcode_(identifier)):[2021A&A...650A.201R](https://ui.adsabs.harvard.edu/abs/2021A&A...650A.201R). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202140985](https://doi.org/10.1051%2F0004-6361%2F202140985). [S2CID](/source/S2CID_(identifier)) [233476431](https://api.semanticscholar.org/CorpusID:233476431). Data available at [https://gruze.org/10pc/](https://gruze.org/10pc/) [Archived](https://web.archive.org/web/20230312171927/http://gruze.org/10pc/) 12 March 2023 at the [Wayback Machine](/source/Wayback_Machine)

1. **[^](#cite_ref-rhoads1971_10-0)** Rhoads, Jack W. (November 15, 1971), [*Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars*](https://ntrs.nasa.gov/api/citations/19720005197/downloads/19720005197.pdf) (PDF), Jet Propulsion Laboratory, California Institute of Technology.

1. ^ [***a***](#cite_ref-allen1899_11-0) [***b***](#cite_ref-allen1899_11-1) Allen, R. H. (1899), [*Star Names: Their Lore and Meaning*](https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Draco*.html), p. 210

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1. **[^](#cite_ref-Ridpath_13-0)** [Ridpath, Ian](/source/Ian_Ridpath). ["Star Tales - Draco"](http://ianridpath.com/startales/draco.html). Retrieved 10 May 2025.

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## External links

- [ARICNS](https://web.archive.org/web/20051024072413/http://www.ari.uni-heidelberg.de/aricns/cnspages/4c01485.htm)

- [Chi Draconis 2](https://web.archive.org/web/20000824113925/http://www.solstation.com/stars/chidrac2.htm) at SolStation.

- [nStars database entry](https://web.archive.org/web/20050928213551/http://nstars.arc.nasa.gov/searches/starinfo.cfm?partb=1821p7243&starpage=0)

v t e Constellation of Draco List of stars in Draco Draco in Chinese astronomy Stars Bayer α (Thuban) β (Rastaban) γ (Eltanin) δ (Altais) ε (Tyl) ζ (Aldhibah) η (Athebyne) θ ι (Edasich) κ λ (Giausar) μ (Alrakis) ν (Kuma) ξ (Grumium) ο π ρ σ (Alsafi) τ υ φ χ ψ1 (Dziban) ψ2 ω Flamsteed 4 6 7 (Tianyi) 8 (Taiyi) 10 (i) 15 (A) 18 (g) 19 (h) 26 36 39 (b) 42 (Fafnir) 45 (d) 50 59 64 (e) 68 Variable TW YY AG BY CL CM CX DO EK HP V581 HR 3751 4126 4934 5811 6237 6518 6618 (Alruba) 6817 7137 7783 HD 109246 (Funi) 101364 128717 147379 156279 158259 176693 191939 Other 2MASS 1237+6526 2MASS J17554042+6551277 G 240-72 GD 356 Gliese 420 Gliese 625 Gliese 687 GRW +70 8247 Kepler-4 Kepler-10 Kepler-12 Kepler-90 Kepler-296 KOI-256 LP 71-82 Qatar-1 SDSS J1240+6710 Struve 2398 TOI-1136 WD 1856+534 WISE 1647+5632 WISE 1841+7000 Exoplanets HD 139357 b HD 167042 b ι Dra b (Hypatia) Kepler-4b Kepler-10b c Kepler-12b Kepler-90e f g h i Kepler-296b c d e f TOI-1452 b TrES-2b Star clusters LAMOST 1 Nebulae Cat's Eye Nebula NGC 6742 Galaxies NGC 3147 3197 3735 4121 4125 4221 4236 4319 4331 4332 4363 4441 4513 4545 4589 5678 5777 5866 5866B 5879 5905 5907 5949 5963 5965 5982 5985 6090 6248 6285 6286 6338 6340 6365 6373 6394 6412 6503 6505 6566 6621 6622 6670 6676 6786 6789 Other 1ES 1927+654 1ES 1959+650 3C 249.1 3C 305 3C 319 3C 343 3C 343.1 3C 351 3C 356 3C 371 3C 380 3C 390.3 3C 401 4C +72.26 4C 73.08 8C 1241+735 Abell 2218 BCG Bean galaxy Beaver galaxy BZQ J1727+5510 Draco Dwarf Draco II GB 1508+5714 Goldfish galaxy H1821+643 HFLS3 IERS B1946+708 IRAS F17179+5444 IRAS 18580+6527 J120011.1+680924.8 KKR 25 Markarian 817 Markarian 876 Original TRG PGC 39058 Porphyrion QSO B1823+568 RGZ J172749.5+534647 S5 1803+784 S5 2007+777 SDSS J1715+6008 Tadpole Galaxy UGC 9391 UGC 9405 UGC 11241 UGC 11411 WISEA J145223.62+611707.5 WN B1851+5707 Galaxy clusters Abell 2218 CL1358+62 Draco Supercluster NGC 5866 Group Astronomical events SN 2003jb SN 2005B SN 2016aps Swift J1644+57 Category

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Adapted from the Wikipedia article [Chi Draconis](https://en.wikipedia.org/wiki/Chi_Draconis) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Chi_Draconis?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.