| prop_mo_ra = {{nowrap|65.17 ± 0.42[1]}}
| prop_mo_dec = {{nowrap|1.74 ± 0.30[1]}}
| parallax = 5.72
| p_error = 0.38
| parallax_footnote = [1]
| absmag_v =−0.43[12]
}}{{Starbox detail
| mass = 0.98[13]
| radius = 227[13]
| luminosity = 5,888[13]
| temperature = 3,373[13]
| metal_fe =
| gravity =
| rotational_velocity =
| age =
}}{{Starbox catalog
| names = W Cyg, HR 8262, HD 205730, BD+44°3877, HIP 106642
}}{{Starbox reference
| Simbad = W+Cygni
}}{{Starbox end}}W Cygni is a semi-regular variable star in the constellation Cygnus, located 570 light-years from Earth. It lies less than half a degree southeast of ρ Cygni.
Discovery
W Cygni is, at times, a naked-eye star but it was not given a Bayer or Flamsteed designation. It was discovered to be variable by John Ellard Gore, and first published in 1885.[17]
Variability
W Cygni has a maximum magnitude of 5.10 and a minimum magnitude 6.83. It is catalogued as having a primary period of 131.7 days, but shows variations with a variety of periods around 131 days as well as 234 days.[18][17] It is believed to be pulsating in the first overtone.[13]
Properties
W Cygni is a red giant on the asymptotic giant branch (AGB). Its spectral type ranges between M4e and M6e, and it shows possible elevated levels of Technetium.[3] The masses of AGB stars are poorly known, but using the pulsation properties of W Cygni, it mass is calculated to be slightly less than the sun's.[13]
Companion
W Cygni has been proposed as a binary star with a hotter main sequence companion, but it has not been confirmed.[23]
References
1. ^1 {{citation | title=Mg II chromospheric radiative loss rates in cool active and quiet stars | last1=Cardini | first1=D. | postscript=. | journal=Astronomy and Astrophysics | volume=430 | pages=303–311 | date=January 2005 | doi=10.1051/0004-6361:20041440 | bibcode=2005A&A...430..303C |arxiv = astro-ph/0409683 }}
2. ^1 {{cite journal|bibcode=2016MNRAS.461.3036O|arxiv=1606.09086|title=Ultraviolet emission from main-sequence companions of AGB stars|journal=Monthly Notices of the Royal Astronomical Society|volume=461|issue=3|pages=3036|author1=Ortiz|first1=Roberto|last2=Guerrero|first2=Martín A.|year=2016|doi=10.1093/mnras/stw1547}}
3. ^1 {{cite journal|bibcode=2007MNRAS.378.1543G|arxiv=0704.3150|title=Semiregular variables in the solar neighbourhood|journal=Monthly Notices of the Royal Astronomical Society|volume=378|issue=4|pages=1543|author1=Glass|first1=I. S.|last2=Van Leeuwen|first2=F.|year=2007|doi=10.1111/j.1365-2966.2007.11903.x}}
4. ^1 2 {{cite journal|bibcode=2012arXiv1203.6467S|arxiv=1203.6467|title=John Ellard Gore: Of immensity and minuteness|volume=1203|pages=arXiv:1203.6467|author1=Shears|first1=Jeremy|year=2012}}
5. ^1 {{cite journal|bibcode=2011ARep...55...31S|title=Search for and study of hot circumstellar dust envelopes|journal=Astronomy Reports|volume=55|pages=31|author1=Shenavrin|first1=V. I.|last2=Taranova|first2=O. G.|last3=Nadzhip|first3=A. E.|year=2011|doi=10.1134/S1063772911010070}}
6. ^1 2 {{cite web|url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=10926 |title=W Cygni |date=10 July 2017|work=AAVSO Website|publisher=American Association of Variable Star Observers|accessdate=31 December 2013}}
7. ^1 {{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S|volume=1|display-authors=etal|author1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}
8. ^1 2 {{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|pages=0|author1=Ducati|first1=J. R.|year=2002}}
9. ^1 2 3 4 5 {{cite journal | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653 | year=2007 | last1=Van Leeuwen | first1=F. }} Vizier catalog entry
10. ^1 2 3 4 5 6 {{cite journal|bibcode=2013PASJ...65...60T|title=A Method to Estimate the Masses of Asymptotic Giant Branch Variable Stars|journal=Publications of the Astronomical Society of Japan|volume=65|issue=3|pages=60|author1=Takeuti|first1=Mine|last2=Nakagawa|first2=Akiharu|last3=Kurayama|first3=Tomoharu|last4=Honma|first4=Mareki|year=2013|doi=10.1093/pasj/65.3.60}}