# 39 Draconis

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Wide binary star system in the constellation of Draco

This article is about b Draconis; not to be confused with [β (beta) Draconis](/source/Beta_Draconis).

39 Draconis Location of 39 Draconis (circled in red) Observation data Epoch J2000 Equinox ICRS Constellation Draco[1] A Right ascension 18h 23m 54.60689s[2] Declination +58° 48′ 02.6667″[2] Apparent magnitude (V) 5.06[3] B Right ascension 18h 23m 54.51639s[4] Declination +58° 48′ 06.3674″[4] Apparent magnitude (V) 8.07[3] Characteristics Evolutionary stage main sequence[2][5] Spectral type A1V + F5V[6] U−B color index +0.06[7] B−V color index +0.10[7] Astrometry Radial velocity (Rv) −24.53±0.23[8] km/s A Proper motion (μ) RA: −37.322[2] mas/yr Dec.: +62.892[2] mas/yr Parallax (π) 17.1615±0.0631 mas[2] Distance 190.1 ± 0.7 ly (58.3 ± 0.2 pc) Absolute magnitude (MV) +1.31[9] B Proper motion (μ) RA: −41.742[4] mas/yr Dec.: +61.076[4] mas/yr Parallax (π) 17.2293±0.0219 mas[4] Distance 189.3 ± 0.2 ly (58.04 ± 0.07 pc) Absolute magnitude (MV) +4.32[9] Orbit[3] Period (P) 4,000±200 yr Semi-major axis (a) 6.6±0.3″ Eccentricity (e) 0.553±0.005 Inclination (i) 107.7±0.12° Longitude of the node (Ω) 179.9±0.10° Periastron epoch (T) 5671.40±12.08 Argument of periastron (ω) (secondary) 128.0±2.2° Details 39 Dra A Mass 2.12[9] M☉ Radius 2.3[10] R☉ Luminosity 27[10] L☉ Surface gravity (log g) 4.04[10] cgs Temperature 8,630[10] K Rotational velocity (v sin i) 186[5] km/s Age 350[11] Myr 39 Dra B Mass 1.18[9] M☉ Radius 1.15[10] R☉ Luminosity 1.85[10] L☉ Surface gravity (log g) 4.40[10] cgs Temperature 6,271[10] K Rotation 5.9 days[12] Age 2.6[13] Gyr Other designations b Dra, 39 Dra, BD+58°1809, HD 170073, HIP 90156, HR 6923, SAO 30949[14] Database references SIMBAD 39 Dra 39 Dra A 39 Dra B

**39 Draconis** is a wide [binary star](/source/Binary_star) system in the northern [circumpolar constellation](/source/Circumpolar_constellation) of [Draco](/source/Draco_(constellation)). It has the [Bayer designation](/source/Bayer_designation) **b Draconis**, while *39 Draconis* is the [Flamsteed designation](/source/Flamsteed_designation). This system is visible to the naked eye as a dim, white-hued point of light with a combined [apparent visual magnitude](/source/Apparent_visual_magnitude) of 5.0.[1] [Parallax measurements](/source/Stellar_parallax) made by the [Gaia spacecraft](/source/Gaia_spacecraft) put it at a distance of 190 light-years, or 58 parsecs away from the Sun. The system is moving closer to the Earth with a heliocentric [radial velocity](/source/Radial_velocity) of −24.5 km/s.[8]

The two components of 39 Draconis have an [angular separation](/source/Angular_separation) of 6.621[″](/source/Second_of_arc) and take almost 4,000 years to orbit each other.[3] The primary star is an early [A-type main-sequence star](/source/A-type_main-sequence_star), having 2.12 times the [mass of the Sun](/source/Mass_of_the_Sun) with a visual magnitude of 5.06.[3] The secondary is a magnitude 8.07[3] [F-type main-sequence star](/source/F-type_main-sequence_star), and has 1.18 times the mass of the Sun.[9]

The 8th-magnitude star HD 238865 is listed in double star catalogues as component C.[15] It is separated from the other two stars by 90[″](/source/Second_of_arc) and lies at about the same distance.[16] It is itself a [spectroscopic binary](/source/Spectroscopic_binary) with an F8 primary and a red dwarf secondary orbiting every 2.7 days.[17][18]

## References

1. ^ [***a***](#cite_ref-xhip_1-0) [***b***](#cite_ref-xhip_1-1) Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". *[Astronomy Letters](/source/Astronomy_Letters)*. **38** (5): 331. [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971). [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A). [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015). [XHIP record for this object](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-ref=VIZ681510a8389ecb&-out.src=V%2F137D%2FXHIP&-nav=cat%3AV%2F137D%26tab%3A{V%2F137D%2FXHIP}%26key%3Asource%3DV%2F137D%2FXHIP%26HTTPPRM%3A&-source=V%2F137D%2FXHIP&-out=HIP&HIP=90156&-out=Comp&-out=Gr&-out=RAJ2000&-out=DEJ2000&-out=Dist&-out=X&-out=Y&-out=Z&-out=SpType&-out=Simbad&-out=Hpmag&-out=Lum&-out=Cst) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-dr3a_2-0) [***b***](#cite_ref-dr3a_2-1) [***c***](#cite_ref-dr3a_2-2) [***d***](#cite_ref-dr3a_2-3) [***e***](#cite_ref-dr3a_2-4) [***f***](#cite_ref-dr3a_2-5) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D2157548616097840000%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-ORB6_3-0) [***b***](#cite_ref-ORB6_3-1) [***c***](#cite_ref-ORB6_3-2) [***d***](#cite_ref-ORB6_3-3) [***e***](#cite_ref-ORB6_3-4) [***f***](#cite_ref-ORB6_3-5) ["Sixth Catalog of Orbits of Visual Binary Stars"](https://web.archive.org/web/20170801102553/http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6). *United States Naval Observatory*. Archived from [the original](http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6) on 2017-08-01. Retrieved 2017-06-22.

1. ^ [***a***](#cite_ref-dr3b_4-0) [***b***](#cite_ref-dr3b_4-1) [***c***](#cite_ref-dr3b_4-2) [***d***](#cite_ref-dr3b_4-3) [***e***](#cite_ref-dr3b_4-4) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D2157548616097840128%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-zorec2012_5-0) [***b***](#cite_ref-zorec2012_5-1) Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". *Astronomy and Astrophysics*. **537**: A120. [arXiv](/source/ArXiv_(identifier)):[1201.2052](https://arxiv.org/abs/1201.2052). [Bibcode](/source/Bibcode_(identifier)):[2012A&A...537A.120Z](https://ui.adsabs.harvard.edu/abs/2012A&A...537A.120Z). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201117691](https://doi.org/10.1051%2F0004-6361%2F201117691).

1. **[^](#cite_ref-Lutz_6-0)** Lutz, T. E.; [Lutz, J. H.](/source/Julie_Lutz) (1977). ["Spectral classification and UBV photometry of bright visual double stars"](https://doi.org/10.1086%2F112066). *The Astronomical Journal*. **82**: 431. [Bibcode](/source/Bibcode_(identifier)):[1977AJ.....82..431L](https://ui.adsabs.harvard.edu/abs/1977AJ.....82..431L). [doi](/source/Doi_(identifier)):[10.1086/112066](https://doi.org/10.1086%2F112066).

1. ^ [***a***](#cite_ref-EgUBV_7-0) [***b***](#cite_ref-EgUBV_7-1) Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". *Catalogue of Eggen's UBV Data*. [Bibcode](/source/Bibcode_(identifier)):[1986EgUBV........0M](https://ui.adsabs.harvard.edu/abs/1986EgUBV........0M).

1. ^ [***a***](#cite_ref-SB9_8-0) [***b***](#cite_ref-SB9_8-1) Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". *Astronomy and Astrophysics*. **424** (2): 727–732. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0406573](https://arxiv.org/abs/astro-ph/0406573). [Bibcode](/source/Bibcode_(identifier)):[2004A&A...424..727P](https://ui.adsabs.harvard.edu/abs/2004A&A...424..727P). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20041213](https://doi.org/10.1051%2F0004-6361%3A20041213). [S2CID](/source/S2CID_(identifier)) [119387088](https://api.semanticscholar.org/CorpusID:119387088).

1. ^ [***a***](#cite_ref-Novakovic_9-0) [***b***](#cite_ref-Novakovic_9-1) [***c***](#cite_ref-Novakovic_9-2) [***d***](#cite_ref-Novakovic_9-3) [***e***](#cite_ref-Novakovic_9-4) Novakovic, B.; Todorovic, N. (2006). ["Orbits of four double stars"](https://doi.org/10.2298%2FSAJ0672021N). *Serbian Astronomical Journal*. **172** (172): 21. [Bibcode](/source/Bibcode_(identifier)):[2006SerAJ.172...21N](https://ui.adsabs.harvard.edu/abs/2006SerAJ.172...21N). [doi](/source/Doi_(identifier)):[10.2298/SAJ0672021N](https://doi.org/10.2298%2FSAJ0672021N). [S2CID](/source/S2CID_(identifier)) [55352155](https://api.semanticscholar.org/CorpusID:55352155).

1. ^ [***a***](#cite_ref-tic_10-0) [***b***](#cite_ref-tic_10-1) [***c***](#cite_ref-tic_10-2) [***d***](#cite_ref-tic_10-3) [***e***](#cite_ref-tic_10-4) [***f***](#cite_ref-tic_10-5) [***g***](#cite_ref-tic_10-6) [***h***](#cite_ref-tic_10-7) Stassun, Keivan G.; et al. (2019). ["The Revised TESS Input Catalog and Candidate Target List"](https://doi.org/10.3847%2F1538-3881%2Fab3467). *The Astronomical Journal*. **158** (4): 138. [arXiv](/source/ArXiv_(identifier)):[1905.10694](https://arxiv.org/abs/1905.10694). [Bibcode](/source/Bibcode_(identifier)):[2019AJ....158..138S](https://ui.adsabs.harvard.edu/abs/2019AJ....158..138S). [doi](/source/Doi_(identifier)):[10.3847/1538-3881/ab3467](https://doi.org/10.3847%2F1538-3881%2Fab3467).

1. **[^](#cite_ref-derosa2014_11-0)** De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014). ["The VAST Survey - III. The multiplicity of A-type stars within 75 pc"](https://doi.org/10.1093%2Fmnras%2Fstt1932). *Monthly Notices of the Royal Astronomical Society*. **437** (2): 1216. [arXiv](/source/ArXiv_(identifier)):[1311.7141](https://arxiv.org/abs/1311.7141). [Bibcode](/source/Bibcode_(identifier)):[2014MNRAS.437.1216D](https://ui.adsabs.harvard.edu/abs/2014MNRAS.437.1216D). [doi](/source/Doi_(identifier)):[10.1093/mnras/stt1932](https://doi.org/10.1093%2Fmnras%2Fstt1932).

1. **[^](#cite_ref-lin2024_12-0)** Lin, Chia-Lung; Apai, Dániel; Giampapa, Mark S.; Ip, Wing-Huen (2024). ["Scalable, Advanced Machine Learning Based Approaches for Stellar Flare Identification: Application to TESS Short-cadence Data and Analysis of a New Flare Catalog"](https://doi.org/10.3847%2F1538-3881%2Fad7956). *The Astronomical Journal*. **168** (6): 234. [arXiv](/source/ArXiv_(identifier)):[2409.02540](https://arxiv.org/abs/2409.02540). [Bibcode](/source/Bibcode_(identifier)):[2024AJ....168..234L](https://ui.adsabs.harvard.edu/abs/2024AJ....168..234L). [doi](/source/Doi_(identifier)):[10.3847/1538-3881/ad7956](https://doi.org/10.3847%2F1538-3881%2Fad7956).

1. **[^](#cite_ref-ware2022_13-0)** Ware, Austin; Young, Patrick; Truitt, Amanda; Spacek, Alexander (2022). ["Continuous Habitable Zones: Using Bayesian Methods to Prioritize Characterization of Potentially Habitable Worlds"](https://doi.org/10.3847%2F1538-4357%2Fac5c4e). *The Astrophysical Journal*. **929** (2): 143. [arXiv](/source/ArXiv_(identifier)):[2203.06259](https://arxiv.org/abs/2203.06259). [Bibcode](/source/Bibcode_(identifier)):[2022ApJ...929..143W](https://ui.adsabs.harvard.edu/abs/2022ApJ...929..143W). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/ac5c4e](https://doi.org/10.3847%2F1538-4357%2Fac5c4e).

1. **[^](#cite_ref-SIMBAD_14-0)** ["* b Dra"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+b+Dra). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 21 June 2017.

1. **[^](#cite_ref-wds_15-0)** Mason, B. D.; et al. (2014). ["The Washington Visual Double Star Catalog"](https://doi.org/10.1086%2F323920). *The Astronomical Journal*. **122** (6): 3466–3471. [Bibcode](/source/Bibcode_(identifier)):[2001AJ....122.3466M](https://ui.adsabs.harvard.edu/abs/2001AJ....122.3466M). [doi](/source/Doi_(identifier)):[10.1086/323920](https://doi.org/10.1086%2F323920).

1. **[^](#cite_ref-dr2c_16-0)** [Brown, A. G. A.](/source/Anthony_Brown_(scientist)); et al. ([Gaia collaboration](/source/Data_Processing_and_Analysis_Consortium)) (August 2018). ["*Gaia* Data Release 2: Summary of the contents and survey properties"](https://doi.org/10.1051%2F0004-6361%2F201833051). *[Astronomy & Astrophysics](/source/Astronomy_%26_Astrophysics)*. **616**. A1. [arXiv](/source/ArXiv_(identifier)):[1804.09365](https://arxiv.org/abs/1804.09365). [Bibcode](/source/Bibcode_(identifier)):[2018A&A...616A...1G](https://ui.adsabs.harvard.edu/abs/2018A&A...616A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201833051](https://doi.org/10.1051%2F0004-6361%2F201833051). [Gaia DR2 record for this source](https://vizier.u-strasbg.fr/viz-bin/VizieR-S?Gaia%20DR2%202157548753536798208) at [VizieR](/source/VizieR).

1. **[^](#cite_ref-derosa_17-0)** De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014). ["The VAST Survey - III. The multiplicity of A-type stars within 75 pc"](https://doi.org/10.1093%2Fmnras%2Fstt1932). *Monthly Notices of the Royal Astronomical Society*. **437** (2): 1216. [arXiv](/source/ArXiv_(identifier)):[1311.7141](https://arxiv.org/abs/1311.7141). [Bibcode](/source/Bibcode_(identifier)):[2014MNRAS.437.1216D](https://ui.adsabs.harvard.edu/abs/2014MNRAS.437.1216D). [doi](/source/Doi_(identifier)):[10.1093/mnras/stt1932](https://doi.org/10.1093%2Fmnras%2Fstt1932). [S2CID](/source/S2CID_(identifier)) [88503488](https://api.semanticscholar.org/CorpusID:88503488).

1. **[^](#cite_ref-tokovinin_18-0)** Tokovinin, A. A.; Smekhov, M. G. (1995). "Spectroscopic components in multiple systems: ADS 11336C". *Astronomy Letters*. **21** (2): 247. [Bibcode](/source/Bibcode_(identifier)):[1995AstL...21..247T](https://ui.adsabs.harvard.edu/abs/1995AstL...21..247T).

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 [39 Draconis](https://en.wikipedia.org/wiki/39_Draconis) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/39_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.