{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox observe 2s | epoch=J2000 | constell=[[Draco (constellation)|Draco]] | component1=AB | ra1={{RA|17|34|59.62474}}<ref name=GaiaDR3a/> | dec1={{DEC|+61|52|28.2418}}<ref name=GaiaDR3a/> | appmag_v1=5.236<ref name=aaass65_2_405/> | component2=C | ra2={{RA|17|35|34.47852}}<ref name=GaiaDR3c/> | dec2={{DEC|+61|40|53.6281}}<ref name=GaiaDR3c/> | appmag_v2=9.97<ref name="Pinamonti2019"/> }} {{Starbox character | component1=AB | type=[[main sequence]]<ref name=GaiaDR3a/> | class=G0Va (F9V + K3V)<ref name=aj81_245/> | b-v=+0.595<ref name=aaass65_2_405/> | u-b=+0.100<ref name=aaass65_2_405/> | variable= | component2=C | type2=[[main sequence]]<ref name=GaiaDR3c/> | class2=M0.5V<ref name="Pinamonti2019"/> | b-v2=+1.48<ref name="Pinamonti2019"/> }} {{Starbox astrometry | component1=AB | radial_v={{val|-15.72|0.33}}<ref name=GaiaDR3a/> | prop_mo_ra=236.247 | prop_mo_dec=−466.111 | pm_footnote=<ref name=GaiaDR3a/> | parallax=69.2832 | p_error=0.2004 | parallax_footnote=<ref name=GaiaDR3a/> | absmag_v={{Val|4.58|0.011}}<ref name=park2013/> | component2=C | radial_v2={{val|-15.53|0.16}}<ref name=GaiaDR3c/> | prop_mo_ra2=261.923 | prop_mo_dec2=−514.499 | pm_footnote2=<ref name=GaiaDR3c/> | parallax2=69.8921 | p_error2=0.0153 | parallax_footnote2=<ref name=GaiaDR3c/> }} {{Starbox orbit | reference = <ref name=ORB6>{{cite web|url=http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|title=Sixth Catalog of Orbits of Visual Binary Stars|work=United States Naval Observatory|accessdate=25 March 2017|archive-date=30 April 2017|archive-url=https://web.archive.org/web/20170430161106/http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|url-status=dead}}</ref> | primary = 26 Dra A | name = 26 Dra B | period = 76.1 | axis = 1.53 | inclination = 104 | node = 151 | periastron = 1947 | eccentricity = 0.18 | periarg = 307 }} {{Starbox detail | component1=AB | mass=1.30/0.83<ref name="aj67"/> | radius= | luminosity= | temperature=6,000<ref name="apj131"/> | metal_fe=−0.18<ref name="apj687" /> | rotation= | rotational_velocity=10<ref name=bernacca1970/> | gravity=4.50<ref name="apj131" /> | age_gyr=8.4–11.5<ref name="apj687" /> | component2=C | mass2={{val|0.55|0.06}}<ref name="Pinamonti2019"/> | radius2={{val|0.54|0.05}}<ref name="Pinamonti2019"/> | gravity2={{val|4.72|0.05}}<ref name="Pinamonti2019"/> | temperature2={{val|3816|69}}<ref name="Pinamonti2019"/> | metal_fe2={{val|−0.15|0.09}}<ref name="Pinamonti2019"/> | rotation2={{val|18.15|0.15|0.16|ul=d}}<ref name="Pinamonti2019"/> | rotational_velocity2={{val|1.33|0.42}}<ref name="Pinamonti2019"/> }} {{Starbox catalog | names={{odlist | ADS=10660 | CCDM=J17351+6152 | WDS=J17350+6153}} | component1=AB | names1={{odlist | F=26 Dra | BD=+61 1678 | GJ=684 | HD=160269 | HIP=86036 | HR=6573 | LHS=3305 | LTT=15223 | SAO=17546}}<ref name="SIMBAD"/> | component2=C | names2={{odlist | G=226-66 | GJ=685 | HIP=86087 | LHS=3306 | LTT=15224}}<ref name=SIMBAD3/> }} {{Starbox reference | Simbad = 26+Dra|sn=A | Simbad2 = 26+Dra+B|sn2=B | Simbad3 = GJ+685|sn3=C }} {{Starbox end}}
'''26 Draconis''' is a triple [[star]] system<ref>{{cite journal | author=Greaves, J. S. | author2=Wyatt, M. C. |date=November 2003 | title=Some anomalies in the occurrence of debris discs around main-sequence A and G stars | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=345 | issue=4 | pages=1212–1222 | doi=10.1046/j.1365-2966.2003.07037.x | bibcode=2003MNRAS.345.1212G | doi-access=free}}</ref> in the [[constellation]] [[Draco (constellation)|Draco]], located 47 [[light-year]]s from the [[Sun]]. Two of the system components, A and B, form a [[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.<ref name=aj81_245/> A 1962 study estimated the masses of these two stars as 1.30 and 0.83 times the [[Solar mass|mass of the Sun]], respectively.<ref name="aj67" /> 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.<ref name="apj687">{{cite journal | last1=Makarov | first1=V. V. | last2=Zacharias | first2=N. | last3=Hennessy | first3=G. S. | title=Common Proper Motion Companions to Nearby Stars: Ages and Evolution | journal=The Astrophysical Journal | volume=687 | issue=1 | pages=566–578 |date=November 2008 | doi=10.1086/591638 | bibcode=2008ApJ...687..566M |arxiv = 0808.3414 | s2cid=17811620 }}</ref>
The [[Space velocity (astronomy)|space velocity]] components of 26 Draconis are U = +36.5, V = −4.3 and W = −21.8 km/s.<ref>{{cite journal | author=Soderblom, David R. | author2=Mayor, Michel |date=January 1993 | title=Stellar kinematic groups. I - The Ursa Major group | journal=Astronomical Journal | volume=105| issue=1 | pages=226–249 | doi=10.1086/116422 | bibcode=1993AJ....105..226S | doi-access=free}}</ref> This system is on an orbit through the [[Milky Way]] galaxy that has an [[Eccentricity (orbit)|eccentricity]] of 0.14, taking it as close as {{Convert|23.1|kly|kpc|abbr=on|sigfig=3}} and as far as {{Convert|30.4|kly|kpc|abbr=on|sigfig=3}} from the galactic core. The inclination of this orbit carries the star system as much as {{Convert|0.75|kly|kpc|abbr=on|sigfig=2}} above the plane of the galactic disk.<ref>{{cite journal | author=Holmberg, J. | author2=Nordström, B. | author3=Andersen, J. | title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics | journal=Astronomy and Astrophysics | volume=501 | issue=3 |date=July 2009 | pages=941–947 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H|arxiv = 0811.3982 | s2cid=118577511 }}</ref> This system may be a member of the [[Ursa Major moving group]].<ref>{{cite journal | author=Greaves, J. S. | author2=Wyatt, M. C. | author3=Bryden, G. | title=Debris discs around nearby solar analogues | journal=Monthly Notices of the Royal Astronomical Society | volume=397 | issue=2 |date=August 2009 | pages=757–762(6) | doi=10.1111/j.1365-2966.2009.15048.x | doi-access=free | bibcode=2009MNRAS.397..757G|arxiv = 0907.3677 | s2cid=17758971 }}</ref>
==Gliese 685== The third component, GJ 685, is a [[red dwarf]] with spectral classification of M0V. As of 1970, this star is separated by 737.9 [[arc second]]s from the AB pair and they share a [[common proper motion]].<ref name=lepine/> The star GJ 685 has one known planet in orbit that was detected by [[radial velocity method|radial velocity]].<ref name="Pinamonti2019"/>
{{OrbitboxPlanet begin | name = Gliese 685 | table_ref = <ref name="Pinamonti2019"/> }} {{OrbitboxPlanet | exoplanet = b | mass_earth = {{val|9.0|1.7|1.8|p=≥}} | period = {{val|24.160|0.061|0.047}} | semimajor = {{val|0.1344|0.0052|0.0051}} | eccentricity = }} {{Orbitbox end}}
==References== {{Reflist|30em|refs=
<ref name=GaiaDR3a>{{Cite Gaia DR3|1439121018358632832}}</ref>
<ref name=GaiaDR3c>{{Cite Gaia DR3|1439069444391326208}}</ref>
<ref name=SIMBAD3>{{cite simbad |title=GJ 685 |access-date=18 March 2025}}</ref>
<ref name=park2013>{{citation | display-authors=1 | last1=Park | first1=Sunkyung | last2=Kang | first2=Wonseok | last3=Lee | first3=Jeong-Eun | last4=Lee | first4=Sang-Gak | title=Wilson-Bappu Effect: Extended to Surface Gravity | journal=The Astronomical Journal | volume=146 | issue=4 | pages=73 | year=2013 | doi=10.1088/0004-6256/146/4/73 | bibcode=2013AJ....146...73P | arxiv=1307.0592 | s2cid=119187733 | postscript=. }}</ref>
<ref name="apj131">{{cite journal | author=Luck, R. Earle | author2=Heiter, Ulrike | title=Dwarfs in the Local Region | journal=The Astronomical Journal | volume=131 | issue=6| pages=3069–3092 |date=June 2006 | doi=10.1086/504080 | bibcode=2006AJ....131.3069L | doi-access=free}}</ref>
<ref name="aj67">{{cite journal | last=Upgren | first=A. R. | title=Parallax and orbital motion of the triple system 26 Draconis from photographs taken with the Sproul 24-inch refractor | journal=Astronomical Journal | volume=67 | pages=539–543 |date=October 1962 | doi=10.1086/108760 | bibcode=1962AJ.....67..539U | doi-access=free}}</ref>
<ref name=bernacca1970>{{cite journal | author=Bernacca, P. L. | author2=Perinotto, M. | title=A catalogue of stellar rotational velocities | journal=Contributi Osservatorio Astronomico di Padova in Asiago | volume=239 | issue=1 | date=1970 | page=1 | bibcode=1970CoAsi.239....1B }}</ref>
<ref name="SIMBAD">{{cite simbad | title=HD 160269 | accessdate=2010-02-17 }}</ref>
<ref name=aj81_245>{{citation | last1=Edwards | first1=T. W. | title=MK classification for visual binary components | journal=Astronomical Journal | volume=81 | pages=245–249 | date=April 1976 | doi=10.1086/111879 | bibcode=1976AJ.....81..245E }}</ref>
<ref name=aaass65_2_405>{{citation | last1=Oja | first1=T. | title=UBV photometry of stars whose positions are accurately known. III | journal=Astronomy and Astrophysics Supplement Series | year=1986 | volume=65 | issue=2 | pages=405–4 | bibcode=1986A&AS...65..405O | postscript=. }}</ref>
<ref name=lepine>{{cite journal|bibcode=2007AJ....133..889L|doi=10.1086/510333|arxiv=astro-ph/0610605|title=New Distant Companions to Known Nearby Stars. II. Faint Companions of ''Hipparcos'' ''Stars'' and the Frequency of Wide Binary Systems|journal=The Astronomical Journal|volume=133|issue=3|pages=889–905|year=2007|last1=Lépine|first1=Sébastien|last2=Bongiorno|first2=Bethany|s2cid=16800796}}</ref>
<ref name="Pinamonti2019">{{cite journal |last1=Pinamonti |first1=M. |last2=Sozzetti |first2=A. |last3=Giacobbe |first3=P. |display-authors=etal |date=May 2019 |title=The HADES RV programme with HARPS-N at TNG. XI. GJ 685 b: a warm super-Earth around an active M dwarf |journal=[[Astronomy & Astrophysics]] |volume=625 |issue= |pages=A126 |doi=10.1051/0004-6361/201834969 |arxiv=1903.11853 |bibcode=2019A&A...625A.126P |s2cid=85542910}}</ref>
}}
{{Stars of Draco}}
[[Category:Triple star systems]] [[Category:G-type main-sequence stars]] [[Category:K-type main-sequence stars]] [[Category:M-type main-sequence stars]] [[Category:Solar-type stars]] [[Category:Draco (constellation)]] [[Category:Durchmusterung objects|BD+61 1678]] [[Category:Flamsteed objects|Draconis, 26]] [[Category:Gliese and GJ objects|0684]] [[Category:Henry Draper Catalogue objects|160269]] [[Category:Hipparcos objects|086036]] [[Category:Bright Star Catalogue objects|6573]]