{{Short description|Star in the constellation Draco}} {{about-distinguish2|i Draconis|[[Iota Draconis|ι Draconis]]}} {{Starbox begin}} {{Starbox image | image = {{Location mark |image=Draco constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=10 Draconis |x=850|y=600 }} | caption = Location of 10 Draconis (circled in red) }} {{Starbox observe | epoch = J2000 | constell = [[Draco (constellation)|Draco]]<ref name=Anderson2012/> | ra = {{RA|13|51|25.90451}}<ref name=GaiaDR2/> | dec = {{DEC|+64|43|23.7510}}<ref name=GaiaDR2/> | appmag_v = 4.52 - 4.67<ref name=GCVS-CU-Dra/> }} {{Starbox character | type = [[asymptotic giant branch|AGB]]<ref name=eggen1992/> | class = M3.5 III<ref name=perkins1989/> | b-v = {{Val|1.572|0.010}}<ref name=Anderson2012/> | u-b = | variable = [[Slow_irregular_variable#Type_Lb|LB:]]<ref name=GCVS-CU-Dra/> }} {{Starbox astrometry | radial_v = {{Val|−12.26|0.17}}<ref name=Anderson2012/> | prop_mo_ra = +14.144<ref name=GaiaDR2/> | prop_mo_dec = +3.172<ref name=GaiaDR2/> | parallax = 8.2082 | p_error = 0.2628 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = −0.70<ref name=Anderson2012/> }} {{Starbox detail | source = <ref name=Baines2017/> | mass = {{Val|0.93|0.06}} | radius = {{Val|83.22|2.08|2.16}} | luminosity = {{Val|1031|70|fmt=commas}} | gravity = 1.00 | temperature = {{Val|3584|35|fmt=commas}} | metal_fe = −0.24 | rotational_velocity = | age_gyr = {{Val|10.24|1.40}} }} {{Starbox catalog | names = {{odlist | B=i Dra | F=10 Dra | V=CU Dra | BD=+65°963 | FK5=511 | HD=121130 | HIP=67627 | HR=5226 | SAO=16199 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = 10+Dra }} {{Starbox end}}
'''10 Draconis''' is a single<ref name=Eggleton2008/> [[star]] in the northern [[circumpolar constellation]] of [[Draco (constellation)|Draco]]. It was a latter designation of '''87 Ursae Majoris''',<ref name=Wagman1987/> and is visible to the naked eye with an [[apparent visual magnitude]] of about 4.6.<ref name=GCVS-CU-Dra/> The distance to this star, as determined from its annual [[stellar parallax|parallax shift]] of {{Val|8.2|ul=mas}},<ref name=GaiaDR2/> is around 400 [[light year]]s. It is moving closer with a heliocentric [[radial velocity]] of −12 km/s, and is expected to come to within {{Convert|25.82|pc|ly|sigfig=2|abbr=on|disp=out}} in about 8.6 million years.<ref name=Anderson2012/>
[[File:CUDraLightCurve.png|thumb|left|A [[light curve]] for CU Draconis, plotted from ''[[Hipparcos]]'' data<ref name=HipDataAccess/>]] Estimated to be around 10 billion years old, this is an aging [[red giant]] star with a [[stellar classification]] of M3.5 III.<ref name=perkins1989/> It is a periodic variable with a [[frequency]] of 11.98912 cycles per day and an [[amplitude]] of 0.0254 in magnitude.<ref name=Koen2002/> The [[stellar spectrum|spectrum]] does not show evidence of [[s-process]] enhancement.<ref name=Brown1990/> 10 Dra has 93% of the [[mass of the Sun]] but has expanded to about 83 times the [[Sun's radius]]. The star is radiating over 1,000 times the [[Sun's luminosity]] from its enlarged [[photosphere]] at an [[effective temperature]] of 3,584 K.<ref name=Baines2017/>
{{clear left}} ==References== <references> <ref name=HipDataAccess>{{cite web |title=Hipparcos Tools Interactive Data Access |url=https://www.cosmos.esa.int/web/hipparcos/interactive-data-access |website=Hipparcos |publisher=ESA |access-date=8 December 2021}}</ref>
<ref name=SIMBAD>{{cite simbad | title=HD 40409 | access-date=2018-07-16 }}</ref>
<ref name=GaiaDR2>{{cite DR2}}</ref>
<ref name=GCVS-CU-Dra>{{cite web |title=GCVS Query=CU Dra |publisher=[[General Catalogue of Variable Stars]] @ [[Centre de données astronomiques de Strasbourg|Sternberg Astronomical Institute, Moscow, Russia]] |url=http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=CU+Dra |access-date=2023-04-19}}</ref>
<ref name=Koen2002>{{cite journal | last1=Koen | first1=Chris | last2=Eyer | first2=Laurent | title=New periodic variables from the Hipparcos epoch photometry | journal=Monthly Notices of the Royal Astronomical Society | volume=331 | issue=1 | pages=45–59 | date=March 2002 | doi=10.1046/j.1365-8711.2002.05150.x | doi-access=free | bibcode=2002MNRAS.331...45K | arxiv=astro-ph/0112194 | s2cid=10505995 }}</ref>
<ref name=Anderson2012>{{cite XHIP|67627}}</ref>
<ref name=Wagman1987>{{cite journal | last=Wagman | first=M. | title=Flamsteed's Missing Stars | journal=Journal for the History of Astronomy | volume=18 | page=223 |date=August 1987 | issue=3 | bibcode=1987JHA....18..209W | doi=10.1177/002182868701800305 | s2cid=118445625 }}</ref>
<ref name=perkins1989>{{cite journal | title=The Perkins catalog of revised MK types for the cooler stars | journal=Astrophysical Journal Supplement Series | volume=71 | page=245 | year=1989 | last1=Keenan | first1=Philip C. | last2=McNeil | first2=Raymond C. | bibcode=1989ApJS...71..245K | doi=10.1086/191373 }}</ref>
<ref name=Baines2017>{{cite journal | title=Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer | last1=Baines | first1=E. | last2=Schmitt | first2=H. R. | last3=Zavala | first3=R. T. | last4=Hutter | first4=D. | last5=van Belle | first5=G. T. | journal=The Astronomical Journal | volume=155 | issue=1 | date=December 2017 | page=30 | bibcode=2018AJ....155...30B | doi=10.3847/1538-3881/aa9d8b | arxiv=1712.08109 | s2cid=119427037 | doi-access=free }}</ref>
<ref name=Eggleton2008>{{cite journal | title = A catalogue of multiplicity among bright stellar systems | last1 = Eggleton | first1 = P. P. | last2 = Tokovinin | first2=A. A. | journal = Monthly Notices of the Royal Astronomical Society | volume = 389 | issue = 2 | page = 869 | date = 2008 | doi = 10.1111/j.1365-2966.2008.13596.x | doi-access = free | bibcode = 2008MNRAS.389..869E |arxiv = 0806.2878 | s2cid = 14878976 }}</ref>
<ref name=Brown1990>{{cite journal | title=S stars without technetium - The binary star connection | last1=Brown | first1=Jeffery A. | last2=Smith | first2=Verne V. | last3=Lambert | first3=David L. | last4=Dutchover | first4=Edward Jr. | last5=Hinkle | first5=Kenneth H. | last6=Johnson | first6=Hollis R. | journal=Astronomical Journal | display-authors=1 | volume=99 | date=June 1990 | pages=1930–1940 | doi=10.1086/115475 | bibcode=1990AJ.....99.1930B }}</ref>
<ref name=eggen1992>{{cite journal |bibcode=1992AJ....104..275E |title=Asymptotic Giant Branch Stars Near the Sun |last1=Eggen |first1=Olin J. |journal=The Astronomical Journal |date=1992 |volume=104 |page=275 |doi=10.1086/116239 }}</ref> </references>
{{Stars of Draco}}
[[Category:M-type giants]] [[Category:Slow irregular variables]] [[Category:Draco (constellation)]] [[Category:Bayer objects|Draconis, i]] [[Category:Durchmusterung objects|BD+65 0963]] [[Category:Flamsteed objects|Draconis, 10]] [[Category:Henry Draper Catalogue objects|121130]] [[Category:Hipparcos objects|067627]] [[Category:Bright Star Catalogue objects|5226]] [[Category:Objects with variable star designations|Draconis, CU]] [[Category:Asymptotic-giant-branch stars]]