33 Cygni
{{short description|Single star in the constellation Cygnus}}
{{Starbox begin
| name = 33 Cygni
}}
{{Starbox observe
| epoch = J2000
| constell = Cygnus
| dec = {{DEC|+56|34|03.7999}}
}}
{{Starbox character
| u-b =
| variable =
}}
{{Starbox astrometry
| radial_v = {{Val|−16.13|2.53}}
| parallax = 20.48
| p_error = 0.12
}}
{{Starbox detail
| mass = {{Val|2.33|0.01}}
| luminosity = {{Val|44.3|1.0}}
| temperature = {{Val|8395|97|96|fmt=commas}}
| gravity =
| metal_fe =
| rotational_velocity = 243
}}
{{Starbox catalog
| names = {{odlist | F=33 Cyg | BD=+56°2376 | FK5=758 | HD=192696 | HIP=99655 | HR=7740 | SAO=32378 | WDS=J20145+3648A }}
}}
{{Starbox reference
| Simbad=33+Cyg
}}
{{Starbox end}}
33 Cygni is a single star located 159 light years away in the northern constellation Cygnus. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.28. The star is moving closer to the Earth with a heliocentric radial velocity of −16 km/s. Eggen (1995) listed it as a proper motion candidate for membership in the IC 2391 supercluster.
This star has a stellar classification of A3 IV–Vn, showing a spectrum with traits intermediate between an A-type main-sequence star and an evolving subgiant star. The 'n' suffix indicates "nebulous" absorption lines due to rapid rotation. It is about 400 million years old with a high projected rotational velocity of 243 km/s. This rate of spin is giving the star an oblate shape with a pronounced equatorial bulge that is an estimated 28% wider than the polar radius.
33 Cyg has 2.33 times the mass of the Sun and 2.76 times the Sun's radius. The star is radiating 44 times the Sun's luminosity from its photosphere at an effective temperature of 8,395 K. It displays an infrared excess that suggests an orbiting debris disk with a temperature of 500 K at a mean distance of {{Val|1.80|ul=AU}} from the host star.
References
{{reflist|refs=
{{cite simbad | title=33 Cyg | access-date=2019-01-14 }}
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| journal=Astronomical Journal | postscript=.
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| doi=10.1086/117734 | bibcode=1995AJ....110.2862E }}
| last1=van Belle | first1=Gerard T.
| title=Interferometric observations of rapidly rotating stars
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| volume=20 | issue=1 | page=51 | date=March 2012
| doi=10.1007/s00159-012-0051-2 | postscript=.
| bibcode=2012A&ARv..20...51V |arxiv = 1204.2572 | s2cid=119273474
}}
| title=Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra
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| journal=The Astrophysical Journal Supplement Series
| volume=217 | issue=2 | id=29 | pages=13 | date=April 2015
| doi=10.1088/0067-0049/217/2/29 | bibcode=2015ApJS..217...29B
| arxiv=1503.03874 | s2cid=33968873 | display-authors=1 | postscript=. }}
| title=XHIP: An extended hipparcos compilation
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| 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=Cowley | first1=A. | last2=Cowley | first2=C.
| last3=Jaschek | first3=M. | last4=Jaschek | first4=C.
| title=A study of the bright A stars. I. A catalogue of spectral classifications
| display-authors=1 | journal=Astronomical Journal
| volume=74 | pages=375–406 | date=April 1969 | postscript=.
| doi=10.1086/110819 | bibcode=1969AJ.....74..375C }}
| title=A Comprehensive Census of Nearby Infrared Excess Stars
| last1=Cotten | first1=Tara H. | last2=Song | first2=Inseok
| journal=The Astrophysical Journal Supplement Series
| volume=225 | issue=1 | id=15 | pages=24 | date=July 2016
| doi=10.3847/0067-0049/225/1/15 | bibcode=2016ApJS..225...15C
| arxiv=1606.01134 | s2cid=118438871 | postscript=. | doi-access=free }}
| title=Validation of the new Hipparcos reduction
| last1=van Leeuwen | first1=F.
| journal=Astronomy and Astrophysics
| volume=474 | issue=2 | pages=653–664 | date=2007
| arxiv=0708.1752 | bibcode=2007A&A...474..653V
| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}
| title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities
| last1=Zorec | first1=J. | last2=Royer | first2=F.
| last3=Asplund | first3=Martin | last4=Cassisi | first4=Santi
| last5=Ramirez | first5=Ivan | last6=Melendez | first6=Jorge
| last7=Bensby | first7=Thomas | last8=Feltzing | first8=Sofia
| display-authors=1 | journal=Astronomy and Astrophysics
| volume=537 | pages=A120 | year=2012
| bibcode=2012A&A...537A.120Z | arxiv=1201.2052
| doi=10.1051/0004-6361/201117691 | s2cid=55586789 | postscript=. }}
{{citation | display-authors=1
| title=The VAST Survey - III. The multiplicity of A-type stars within 75 pc
| last1=De Rosa | first1=R. J. | last2=Patience | first2=J.
| last3=Wilson | first3=P. A. | last4=Schneider | first4=A.
| last5=Wiktorowicz | first5=S. J. | last6=Vigan | first6=A.
| last7=Marois | first7=C. | last8=Song | first8=I.
| last9=MacIntosh | first9=B. | last10=Graham | first10=J. R.
| last11=Doyon | first11=R. | last12=Bessell | first12=M. S.
| last13=Thomas | first13=S. | last14=Lai | first14=O.
| journal=Monthly Notices of the Royal Astronomical Society
| volume=437 | issue=2 | pages=1216 | year=2014
| doi=10.1093/mnras/stt1932 | doi-access=free
| arxiv=1311.7141
| bibcode=2014MNRAS.437.1216D | s2cid=88503488
| postscript=. }}
}}
{{Stars of Cygnus}}
Category:A-type main-sequence stars
Category:Cygnus (constellation)