68 Draconis

{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox observe | epoch = J2000 | constell = [[Draco (constellation)|Draco]] | ra = {{RA|20|11|34.872}}<ref name=GaiaDR3/> | dec = {{DEC|+62|04|42.77}}<ref name=GaiaDR3/> | appmag_v = 5.69<ref name=apjss147_1_103/> }} {{Starbox character | class = F5 V<ref name=apjss147_1_103/> | b-v = 0.48<ref name=aaa493_3_1099/> | u-b = | variable = }} {{Starbox astrometry | radial_v = −14.6<ref name="Nordström2004"/> | prop_mo_ra = +142.267 | prop_mo_dec = +72.842 | pm_footnote = <ref name=GaiaDR3/> | parallax = 20.9232 | p_error = 0.065 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = 2.33<ref name="Holmberg2009"/> }} {{Starbox detail | mass = 1.15<ref name=David2015/> | radius = | gravity = 3.95<ref name=aaa493_3_1099/> | metal_fe = 0.20<ref name="Holmberg2009"/> | temperature = 6,137<ref name=aaa493_3_1099/> | luminosity = 10.73<ref name=Anderson2012/> | rotational_velocity = 15.1<ref name=aaa493_3_1099/> | rotation = | age_gyr = 1.7<ref name="Holmberg2009"/> }} {{Starbox catalog | names = {{odlist | F=68 Dra | BD=+61°1983 | HD=192455 | HIP=99500 | HR=7727 | SAO=18751 }}<ref name="SIMBAD"/> }} {{Starbox reference | Simbad=68+Dra }} {{Starbox end}}

'''68 Draconis''' is the [[Flamsteed designation]] for a star in the northern [[circumpolar constellation]] of [[Draco (constellation)|Draco]]. It has an [[apparent visual magnitude]] of 5.69,<ref name=apjss147_1_103/> so, according to the [[Bortle scale]], it is faintly visible to the naked eye from suburban skies at night. Measurements made with the [[Gaia (spacecraft)|''Gaia'' spacecraft]] show an annual [[parallax]] shift of {{Val|0.0209232|ul=arcsecond|fmt=commas}},<ref name=GaiaDR3/> which is equivalent to a distance of around {{Convert|156|ly|pc|abbr=on}} from the Sun. It is moving closer to the Earth with a heliocentric [[radial velocity]] of –14.6 km/s.<ref name="Nordström2004"/> The star has a relatively high [[proper motion]], traversing the [[celestial sphere]] at a rate of {{Val|0.150|u=arcsecond}} per year.<ref name=Lepine2005/>

The [[stellar classification]] of 68 Draconis is F5 V,<ref name=apjss147_1_103/> indicating that it is a [[main sequence]] star that is [[hydrogen fusion|fusing hydrogen]] into helium at its [[stellar core|core]] to generate energy. The star appears to be over-luminous for a member of its class, being 0.73 magnitudes brighter than expected. This may indicate that this is a binary system with an unresolved secondary component.<ref name=apjss147_1_103/> It has 15%<ref name=David2015/> more [[solar mass|mass than the Sun]] but is less than half as old, with an estimated age of 1.7 billion years.<ref name="Holmberg2009"/> The star is radiating 11<ref name=Anderson2012/> times the [[Sun's luminosity]] from its [[photosphere]] at an [[effective temperature]] of 6,137 K,<ref name=aaa493_3_1099/> giving it the yellow-white hue of an [[F-type star]].<ref name="csiro"/>

==References== {{Reflist|refs=

<ref name=Lepine2005>{{citation | last1=Lépine | first1=Sébastien | last2=Shara | first2=Michael M. | title=A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog) | journal=The Astronomical Journal | volume=129 | issue=3 | pages=1483–1522 | date=March 2005 | doi=10.1086/427854 | bibcode=2005AJ....129.1483L | arxiv=astro-ph/0412070 | s2cid=2603568 | postscript=. }}</ref>

<ref name=Anderson2012>{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | s2cid=119257644 | postscript=. }}</ref>

<ref name=David2015>{{citation | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | bibcode=2015ApJ...804..146D | arxiv=1501.03154 | doi=10.1088/0004-637X/804/2/146 | s2cid=33401607 | postscript=. }}</ref>

<ref name="Nordström2004">{{citation | display-authors=1 | last1=Nordström | first1=B. | last2=Mayor | first2=M. | last3=Andersen | first3=J. | last4=Holmberg | first4=J. | last5=Pont | first5=F. | last6=Jørgensen | first6=B. R. | last7=Olsen | first7=E. H. | last8=Udry | first8=S. | last9=Mowlavi | first9=N. | title=The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14,000 F and G dwarfs | journal=Astronomy and Astrophysics | volume=418 | pages=989–1019 |date=May 2004 | doi=10.1051/0004-6361:20035959 | bibcode=2004A&A...418..989N |arxiv = astro-ph/0405198 | s2cid=11027621 | postscript=. }}</ref>

<ref name="Holmberg2009">{{citation | last1=Holmberg | first1=J. | last2=Nordström | first2=B. | last3=Andersen | first3=J. | display-authors=1 | title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics | journal=Astronomy and Astrophysics | volume=501 | issue=3 | pages=941–947 |date=July 2009 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H | arxiv=0811.3982 | s2cid=118577511 | postscript=. }}</ref>

<ref name=aaa493_3_1099>{{citation | last1=Schröder | first1=C. | last2=Reiners | first2=Ansgar | last3=Schmitt | first3=Jürgen H. M. M. | title=Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo | journal=Astronomy and Astrophysics | volume=493 | issue=3 | pages=1099–1107 | date=January 2009 | doi=10.1051/0004-6361:200810377 | bibcode=2009A&A...493.1099S | doi-access=free | url=http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9690/aa10377-08.pdf?sequence=2 }}{{Dead link|date=July 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name=apjss147_1_103>{{citation | last1=Griffin | first1=R. F. | last2=Suchkov | first2=A. A. | title=The Nature of Overluminous F Stars Observed in a Radial-Velocity Survey | journal=The Astrophysical Journal Supplement Series | volume=147 | issue=1 | pages=103–144 |date=July 2003 | doi=10.1086/367855 | bibcode=2003ApJS..147..103G | postscript=. | doi-access=free }}</ref>

<ref name="csiro">{{citation |title=The Colour of Stars |date=December 21, 2004 |work=Australia Telescope, Outreach and Education |publisher=[[Commonwealth Scientific and Industrial Research Organisation]] |url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |access-date=2012-01-16 |postscript=. |url-status=dead |archive-url=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |archive-date=March 18, 2012 }}</ref>

<ref name="SIMBAD">{{cite simbad | title=68 Dra | access-date=2013-11-06 }}</ref>

}}

[[Category:F-type main-sequence stars]] [[Category:Draco (constellation)]] [[Category:Bright Star Catalogue objects|7727]] [[Category:Durchmusterung objects|BD+61 1983]] [[Category:Flamsteed objects|Draconis, 68]] [[Category:Henry Draper Catalogue objects|192455]] [[Category:Hipparcos objects|099500]]