68 Draconis
{{Short description|Star in the constellation Draco}}
{{Starbox begin}}
{{Starbox observe
| epoch = J2000
| constell = Draco
}}
{{Starbox character
| u-b =
| variable =
}}
{{Starbox astrometry
| prop_mo_ra = +142.267
| prop_mo_dec = +72.842
| parallax = 20.9232
| p_error = 0.065
}}
{{Starbox detail
| radius =
| rotation =
}}
{{Starbox catalog
| names = {{odlist | F=68 Dra | BD=+61°1983 | HD=192455 | HIP=99500 | HR=7727 | SAO=18751 }}
}}
{{Starbox reference
| Simbad=68+Dra
}}
{{Starbox end}}
68 Draconis is the Flamsteed designation for a star in the northern circumpolar constellation of Draco. It has an apparent visual magnitude of 5.69, 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 show an annual parallax shift of {{Val|0.0209232|ul=arcsecond|fmt=commas}}, 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. The star has a relatively high proper motion, traversing the celestial sphere at a rate of {{Val|0.150|u=arcsecond}} per year.
The stellar classification of 68 Draconis is F5 V, indicating that it is a main sequence star that is fusing hydrogen into helium at its 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. It has 15% more mass than the Sun but is less than half as old, with an estimated age of 1.7 billion years. The star is radiating 11 times the Sun's luminosity from its photosphere at an effective temperature of 6,137 K, giving it the yellow-white hue of an F-type star.
References
{{Reflist|refs=
{{Cite Gaia EDR3|2243923260280193920}}
| 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=. }}
| 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=. }}
| 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=. }}
| 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=.
}}
| 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=.
}}
| 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
}}
|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
}}
| title=68 Dra
| access-date=2013-11-06
}}
}}
{{Stars of Draco}}
{{Sky|20|11|34.91|+|62|04|42.75}}
{{DEFAULTSORT:68 Draconis}}
Category:F-type main-sequence stars