# 26 Draconis

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/26_Draconis
> Markdown URL: https://mediated.wiki/source/26_Draconis.md
> Source: https://en.wikipedia.org/wiki/26_Draconis
> Source revision: 1335885971
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Star in the constellation Draco

26 Draconis Observation data Epoch J2000 Equinox ICRS Constellation Draco AB Right ascension 17h 34m 59.62474s[1] Declination +61° 52′ 28.2418″[1] Apparent magnitude (V) 5.236[2] C Right ascension 17h 35m 34.47852s[3] Declination +61° 40′ 53.6281″[3] Apparent magnitude (V) 9.97[4] Characteristics AB Evolutionary stage main sequence[1] Spectral type G0Va (F9V + K3V)[5] U−B color index +0.100[2] B−V color index +0.595[2] C Evolutionary stage main sequence[3] Spectral type M0.5V[4] B−V color index +1.48[4] Astrometry AB Radial velocity (Rv) −15.72±0.33[1] km/s Proper motion (μ) RA: 236.247 mas/yr[1] Dec.: −466.111 mas/yr[1] Parallax (π) 69.2832±0.2004 mas[1] Distance 47.1 ± 0.1 ly (14.43 ± 0.04 pc) Absolute magnitude (MV) 4.58±0.011[6] C Radial velocity (Rv) −15.53±0.16[3] km/s Proper motion (μ) RA: 261.923 mas/yr[3] Dec.: −514.499 mas/yr[3] Parallax (π) 69.8921±0.0153 mas[3] Distance 46.67 ± 0.01 ly (14.308 ± 0.003 pc) Orbit[7] Primary 26 Dra A Name 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 AB Mass 1.30/0.83[8] M☉ Surface gravity (log g) 4.50[9] cgs Temperature 6,000[9] K Metallicity [Fe/H] −0.18[10] dex Rotational velocity (v sin i) 10[11] km/s Age 8.4–11.5[10] Gyr C Mass 0.55±0.06[4] M☉ Radius 0.54±0.05[4] R☉ Surface gravity (log g) 4.72±0.05[4] cgs Temperature 3816±69[4] K Metallicity [Fe/H] −0.15±0.09[4] dex Rotation 18.15+0.15 −0.16 d[4] Rotational velocity (v sin i) 1.33±0.42[4] km/s Other designations ADS 10660, CCDM J17351+6152, WDS J17350+6153 AB: 26 Dra, BD+61 1678, GJ 684, HD 160269, HIP 86036, HR 6573, SAO 17546, LHS 3305, LTT 15223[12] C: GJ 685, HIP 86087, G 226-66, LHS 3306, LTT 15224[13] Database references SIMBAD A B C

**26 Draconis** is a triple [star](/source/Star) system[14] in the [constellation](/source/Constellation) [Draco](/source/Draco_(constellation)), located 47 [light-years](/source/Light-year) from the [Sun](/source/Sun). Two of the system components, A and B, form a [spectroscopic binary](/source/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.[5] A 1962 study estimated the masses of these two stars as 1.30 and 0.83 times the [mass of the Sun](/source/Solar_mass), respectively.[8] 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.[10]

The [space velocity](/source/Space_velocity_(astronomy)) 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](/source/Milky_Way) galaxy that has an [eccentricity](/source/Eccentricity_(orbit)) 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](/source/Ursa_Major_moving_group).[17]

## Gliese 685

The third component, GJ 685, is a [red dwarf](/source/Red_dwarf) with spectral classification of M0V. As of 1970, this star is separated by 737.9 [arc seconds](/source/Arc_second) from the AB pair and they share a [common proper motion](/source/Common_proper_motion).[18] The star GJ 685 has one known planet in orbit that was detected by [radial velocity](/source/Radial_velocity_method).[4]

The Gliese 685 planetary system[4] 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+0.0052 −0.0051 24.160+0.061 −0.047 — — —

## References

1. ^ [***a***](#cite_ref-GaiaDR3a_1-0) [***b***](#cite_ref-GaiaDR3a_1-1) [***c***](#cite_ref-GaiaDR3a_1-2) [***d***](#cite_ref-GaiaDR3a_1-3) [***e***](#cite_ref-GaiaDR3a_1-4) [***f***](#cite_ref-GaiaDR3a_1-5) 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%3D1439121018358632832%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-aaass65_2_405_2-0) [***b***](#cite_ref-aaass65_2_405_2-1) [***c***](#cite_ref-aaass65_2_405_2-2) Oja, T. (1986), "UBV photometry of stars whose positions are accurately known. III", *Astronomy and Astrophysics Supplement Series*, **65** (2): 405–4, [Bibcode](/source/Bibcode_(identifier)):[1986A&AS...65..405O](https://ui.adsabs.harvard.edu/abs/1986A&AS...65..405O).

1. ^ [***a***](#cite_ref-GaiaDR3c_3-0) [***b***](#cite_ref-GaiaDR3c_3-1) [***c***](#cite_ref-GaiaDR3c_3-2) [***d***](#cite_ref-GaiaDR3c_3-3) [***e***](#cite_ref-GaiaDR3c_3-4) [***f***](#cite_ref-GaiaDR3c_3-5) 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%3D1439069444391326208%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-Pinamonti2019_4-0) [***b***](#cite_ref-Pinamonti2019_4-1) [***c***](#cite_ref-Pinamonti2019_4-2) [***d***](#cite_ref-Pinamonti2019_4-3) [***e***](#cite_ref-Pinamonti2019_4-4) [***f***](#cite_ref-Pinamonti2019_4-5) [***g***](#cite_ref-Pinamonti2019_4-6) [***h***](#cite_ref-Pinamonti2019_4-7) [***i***](#cite_ref-Pinamonti2019_4-8) [***j***](#cite_ref-Pinamonti2019_4-9) [***k***](#cite_ref-Pinamonti2019_4-10) [***l***](#cite_ref-Pinamonti2019_4-11) Pinamonti, M.; Sozzetti, A.; Giacobbe, P.; et al. (May 2019). "The HADES RV programme with HARPS-N at TNG. XI. GJ 685 b: a warm super-Earth around an active M dwarf". *[Astronomy & Astrophysics](/source/Astronomy_%26_Astrophysics)*. **625**: A126. [arXiv](/source/ArXiv_(identifier)):[1903.11853](https://arxiv.org/abs/1903.11853). [Bibcode](/source/Bibcode_(identifier)):[2019A&A...625A.126P](https://ui.adsabs.harvard.edu/abs/2019A&A...625A.126P). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201834969](https://doi.org/10.1051%2F0004-6361%2F201834969). [S2CID](/source/S2CID_(identifier)) [85542910](https://api.semanticscholar.org/CorpusID:85542910).

1. ^ [***a***](#cite_ref-aj81_245_5-0) [***b***](#cite_ref-aj81_245_5-1) Edwards, T. W. (April 1976), "MK classification for visual binary components", *Astronomical Journal*, **81**: 245–249, [Bibcode](/source/Bibcode_(identifier)):[1976AJ.....81..245E](https://ui.adsabs.harvard.edu/abs/1976AJ.....81..245E), [doi](/source/Doi_(identifier)):[10.1086/111879](https://doi.org/10.1086%2F111879)

1. **[^](#cite_ref-park2013_6-0)** Park, Sunkyung; et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", *The Astronomical Journal*, **146** (4): 73, [arXiv](/source/ArXiv_(identifier)):[1307.0592](https://arxiv.org/abs/1307.0592), [Bibcode](/source/Bibcode_(identifier)):[2013AJ....146...73P](https://ui.adsabs.harvard.edu/abs/2013AJ....146...73P), [doi](/source/Doi_(identifier)):[10.1088/0004-6256/146/4/73](https://doi.org/10.1088%2F0004-6256%2F146%2F4%2F73), [S2CID](/source/S2CID_(identifier)) [119187733](https://api.semanticscholar.org/CorpusID:119187733).

1. **[^](#cite_ref-ORB6_7-0)** ["Sixth Catalog of Orbits of Visual Binary Stars"](https://web.archive.org/web/20170430161106/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 30 April 2017. Retrieved 25 March 2017.

1. ^ [***a***](#cite_ref-aj67_8-0) [***b***](#cite_ref-aj67_8-1) Upgren, A. R. (October 1962). ["Parallax and orbital motion of the triple system 26 Draconis from photographs taken with the Sproul 24-inch refractor"](https://doi.org/10.1086%2F108760). *Astronomical Journal*. **67**: 539–543. [Bibcode](/source/Bibcode_(identifier)):[1962AJ.....67..539U](https://ui.adsabs.harvard.edu/abs/1962AJ.....67..539U). [doi](/source/Doi_(identifier)):[10.1086/108760](https://doi.org/10.1086%2F108760).

1. ^ [***a***](#cite_ref-apj131_9-0) [***b***](#cite_ref-apj131_9-1) Luck, R. Earle; Heiter, Ulrike (June 2006). ["Dwarfs in the Local Region"](https://doi.org/10.1086%2F504080). *The Astronomical Journal*. **131** (6): 3069–3092. [Bibcode](/source/Bibcode_(identifier)):[2006AJ....131.3069L](https://ui.adsabs.harvard.edu/abs/2006AJ....131.3069L). [doi](/source/Doi_(identifier)):[10.1086/504080](https://doi.org/10.1086%2F504080).

1. ^ [***a***](#cite_ref-apj687_10-0) [***b***](#cite_ref-apj687_10-1) [***c***](#cite_ref-apj687_10-2) Makarov, V. V.; Zacharias, N.; Hennessy, G. S. (November 2008). "Common Proper Motion Companions to Nearby Stars: Ages and Evolution". *The Astrophysical Journal*. **687** (1): 566–578. [arXiv](/source/ArXiv_(identifier)):[0808.3414](https://arxiv.org/abs/0808.3414). [Bibcode](/source/Bibcode_(identifier)):[2008ApJ...687..566M](https://ui.adsabs.harvard.edu/abs/2008ApJ...687..566M). [doi](/source/Doi_(identifier)):[10.1086/591638](https://doi.org/10.1086%2F591638). [S2CID](/source/S2CID_(identifier)) [17811620](https://api.semanticscholar.org/CorpusID:17811620).

1. **[^](#cite_ref-bernacca1970_11-0)** Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". *Contributi Osservatorio Astronomico di Padova in Asiago*. **239** (1): 1. [Bibcode](/source/Bibcode_(identifier)):[1970CoAsi.239....1B](https://ui.adsabs.harvard.edu/abs/1970CoAsi.239....1B).

1. **[^](#cite_ref-SIMBAD_12-0)** ["HD 160269"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+160269). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2010-02-17.

1. **[^](#cite_ref-SIMBAD3_13-0)** ["GJ 685"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+685). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 18 March 2025.

1. **[^](#cite_ref-14)** Greaves, J. S.; Wyatt, M. C. (November 2003). ["Some anomalies in the occurrence of debris discs around main-sequence A and G stars"](https://doi.org/10.1046%2Fj.1365-2966.2003.07037.x). *[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)*. **345** (4): 1212–1222. [Bibcode](/source/Bibcode_(identifier)):[2003MNRAS.345.1212G](https://ui.adsabs.harvard.edu/abs/2003MNRAS.345.1212G). [doi](/source/Doi_(identifier)):[10.1046/j.1365-2966.2003.07037.x](https://doi.org/10.1046%2Fj.1365-2966.2003.07037.x).

1. **[^](#cite_ref-15)** Soderblom, David R.; Mayor, Michel (January 1993). ["Stellar kinematic groups. I - The Ursa Major group"](https://doi.org/10.1086%2F116422). *Astronomical Journal*. **105** (1): 226–249. [Bibcode](/source/Bibcode_(identifier)):[1993AJ....105..226S](https://ui.adsabs.harvard.edu/abs/1993AJ....105..226S). [doi](/source/Doi_(identifier)):[10.1086/116422](https://doi.org/10.1086%2F116422).

1. **[^](#cite_ref-16)** Holmberg, J.; Nordström, B.; Andersen, J. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". *Astronomy and Astrophysics*. **501** (3): 941–947. [arXiv](/source/ArXiv_(identifier)):[0811.3982](https://arxiv.org/abs/0811.3982). [Bibcode](/source/Bibcode_(identifier)):[2009A&A...501..941H](https://ui.adsabs.harvard.edu/abs/2009A&A...501..941H). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/200811191](https://doi.org/10.1051%2F0004-6361%2F200811191). [S2CID](/source/S2CID_(identifier)) [118577511](https://api.semanticscholar.org/CorpusID:118577511).

1. **[^](#cite_ref-17)** Greaves, J. S.; Wyatt, M. C.; Bryden, G. (August 2009). ["Debris discs around nearby solar analogues"](https://doi.org/10.1111%2Fj.1365-2966.2009.15048.x). *Monthly Notices of the Royal Astronomical Society*. **397** (2): 757–762(6). [arXiv](/source/ArXiv_(identifier)):[0907.3677](https://arxiv.org/abs/0907.3677). [Bibcode](/source/Bibcode_(identifier)):[2009MNRAS.397..757G](https://ui.adsabs.harvard.edu/abs/2009MNRAS.397..757G). [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2009.15048.x](https://doi.org/10.1111%2Fj.1365-2966.2009.15048.x). [S2CID](/source/S2CID_(identifier)) [17758971](https://api.semanticscholar.org/CorpusID:17758971).

1. **[^](#cite_ref-lepine_18-0)** Lépine, Sébastien; Bongiorno, Bethany (2007). "New Distant Companions to Known Nearby Stars. II. Faint Companions of *Hipparcos* *Stars* and the Frequency of Wide Binary Systems". *The Astronomical Journal*. **133** (3): 889–905. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0610605](https://arxiv.org/abs/astro-ph/0610605). [Bibcode](/source/Bibcode_(identifier)):[2007AJ....133..889L](https://ui.adsabs.harvard.edu/abs/2007AJ....133..889L). [doi](/source/Doi_(identifier)):[10.1086/510333](https://doi.org/10.1086%2F510333). [S2CID](/source/S2CID_(identifier)) [16800796](https://api.semanticscholar.org/CorpusID:16800796).

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

---
Adapted from the Wikipedia article [26 Draconis](https://en.wikipedia.org/wiki/26_Draconis) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/26_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.