71 Cygni
{{short description|Star in the constellation Cygnus}}
{{Starbox begin
| name = 71 Cygni
}}
{{Starbox observe
| epoch = J2000
| constell = Cygnus
| dec = {{DEC|+46|32|26.1024}}
}}
{{Starbox character
| type = red clump
| u-b =
| variable =
}}
{{Starbox astrometry
| radial_v = {{Val|−21.54|0.10}}
| parallax = 15.4057
| p_error = 0.1077
}}
{{Starbox detail
| mass = {{Val|2.05|0.09}}
| radius = {{Val|8.31|0.32}}
| luminosity = {{Val|44.7|7.8|6.7}}
| temperature = {{Val|4983|18|fmt=commas}}
| gravity = {{Val|3.03|0.05}}
| metal_fe = {{Val|0.05|0.06}}
| rotational_velocity = {{Val|2.03|0.85}}
| age_gyr = {{Val|1.07|0.15}}
}}
{{Starbox catalog
| names = {{odlist | B=g Cyg | F=71 Cyg | BD=+45°3558 | FK5=807 | HD=204771 | HIP=106093 | HR=8228 | SAO=50934 }}
}}
{{Starbox reference
| Simbad=71+Cyg
}}
{{Starbox end}}
71 Cygni is a star in the northern constellation of Cygnus, located 212 light years from the Sun. 71 Cygni is the Flamsteed designation; it has the Bayer designation g Cygni. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.22. The star is moving closer to the Earth with a heliocentric radial velocity of −21.5 km/s.
At the age of one billion years, this is an evolved giant star with a stellar classification of K0− III, which means it has used up its core hydrogen and expanded. It is a red clump giant, indicating that it is on the horizontal branch of the Hertzsprung–Russell diagram and is generating energy by helium fusion at its center. The star has double the mass of the Sun and eight times the Sun's radius. It is radiating 45 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,983 K.
References
{{reflist|refs=
{{cite simbad | title=71 Cyg | access-date=2019-01-18 }}
{{Cite Gaia DR2|1972198271665518208}}
| 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=Keenan | first1=Philip C. | last2=McNeil | first2=Raymond C.
| title=The Perkins catalog of revised MK types for the cooler stars
| journal=Astrophysical Journal Supplement Series
| volume=71 | pages=245 | year=1989 | postscript=.
| bibcode=1989ApJS...71..245K | doi=10.1086/191373 }}
| last1=Jofré | first1=E. | last2=Petrucci | first2=R.
| last3=Saffe | first3=C. | last4=Saker | first4=L.
| last5=de la Villarmois | first5=E. Artur | last6=Chavero | first6=C.
| last7=Gómez | first7=M. | last8=Mauas | first8=P. J. D.
| title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets
| display-authors=1 | journal=Astronomy & Astrophysics
| volume=574 | pages=A50 | year=2015
| bibcode=2015A&A...574A..50J | arxiv=1410.6422
| doi=10.1051/0004-6361/201424474 | s2cid=53666931 | postscript=. }}
| last1=Valentini | first1=M. | last2=Munari | first2=U.
| title=A spectroscopic survey of faint, high-Galactic-latitude red clump stars. I. The high resolution sample
| journal=Astronomy and Astrophysics
| volume=522 | page=A79 | date=November 2010
| doi=10.1051/0004-6361/201014870 | postscript=.
| bibcode=2010A&A...522A..79V | arxiv=1007.0207 | s2cid=119156545 }}
| display-authors=1 | last1=Mishenina | first1=T. V.
| last2=Bienaymé | first2=O. | last3=Gorbaneva | first3=T. I.
| last4=Charbonnel | first4=C. | last5=Soubiran | first5=C.
| last6=Korotin | first6=S. A. | last7=Kovtyukh | first7=V. V.
| title=Elemental abundances in the atmosphere of clump giants
| journal=Astronomy and Astrophysics
| volume=456 | issue=3 | pages=1109–1120 | date=September 2006
| doi=10.1051/0004-6361:20065141 | postscript=.
| bibcode=2006A&A...456.1109M | arxiv=astro-ph/0605615 | s2cid=18764566 }}
}}
{{Stars of Cygnus}}
Category:Horizontal-branch stars
Category:Cygnus (constellation)