Star in the constellation Cygnus
R Cygni Observation dataEpoch J2000 Equinox J2000 Constellation Cygnus Right ascension 19h 36m 49.35633s [ 1] Declination +50° 11′ 59.7198″[ 1] Apparent magnitude (V)6.1 - 14.4[ 2] Characteristics Spectral type S2.5,9e-S6,9e(Tc)[ 3] Variable type Mira [ 2] Astrometry Proper motion (μ)RA: −3.158[ 1] mas /yr Dec.: −5.755[ 1] mas /yr Parallax (π)1.4835± 0.0963 mas [ 1] Distance 2,200 ± 100 ly pc ) Details Mass 0.85[ 4] M ☉ Luminosity 11,700[ 5] L ☉ Surface gravity (log g )−0.50[ 4] cgs Temperature 2,538[ 4] K Metallicity +0.50[ 4] dex Other designations R Cyg AAVSO 1934+49BD +49 3064HD 185456HIP 31822SAO 31822WDS J19368+5012[ 6] Database references SIMBAD data
R Cygni light curve, showing the period-doubling R Cygni is avariable star of theMira type in the constellationCygnus , less than 4' fromθ Cygni . This is ared giant star on theasymptotic giant branch located around 2,200 light years away. It is anS-type star ranging between spectral types S2.5,9e to S6,9e(Tc).[ 3]
Stars at this mass range andevolutionary stage are pulsationally unstable, displaying a variation in their light output.[ 7] magnitude of 6.1 and a minimum magnitude of 14.4, with a period of 426.45 days.[ 2] N. R. Pogson in 1852, and it has a history of recorded brightness measurements stretching back more than a century.[ 7] [ 7]
TheCatalog of Components of Double and Multiple Stars lists 10th magnitude BD+49 3065 as a companion to R Cygni, at a separation of 91", and both stars lie at approximately the same distance. TheWashington Double Star Catalog additionally lists a 15th magnitude star as a companion at a separation of about 14".[ 8]
^a b c d e Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018)."Gaia Data Release 2: Summary of the contents and survey properties" .Astronomy & Astrophysics 616 . A1.arXiv :1804.09365 Bibcode :2018A&A...616A...1G doi :10.1051/0004-6361/201833051 Gaia DR2 record for this source atVizieR .^a b c Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017). "General catalogue of variable stars: Version GCVS 5.1".Astronomy Reports .61 (1): 80.Bibcode :2017ARep...61...80S .doi :10.1134/S1063772917010085 .S2CID 125853869 . ^a b BSJ (4 January 2010)."R Cygni" .AAVSO Website .American Association of Variable Star Observers . Retrieved21 January 2014 . ^a b c d Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)".Vizier Online Data Catalog .Bibcode :2022yCat.1354....0A . ^ Guandalini, R; Francis, Charles (2010). "Infrared photometry and evolution of mass-losing AGB stars. III. Mass loss rates of MS and S stars".Astronomy and Astrophysics .513 : A4.arXiv :1002.2458 Bibcode :2010A&A...513A...4G .doi :10.1051/0004-6361/200911764 .S2CID 119193286 . ^ "R Cyg" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved30 August 2018 .^a b c Kiss, L. L.; Szatmáry, K. (August 2002). "Period-doubling events in the light curve of R Cygni: Evidence for chaotic behaviour".Astronomy and Astrophysics .390 (2):585– 596.arXiv :astro-ph/0205334 Bibcode :2002A&A...390..585K .doi :10.1051/0004-6361:20020744 .S2CID 17698877 . ^ Mason, Brian D; Wycoff, Gary L; Hartkopf, William I; Douglass, Geoffrey G; Worley, Charles E (2001)."The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog" .The Astronomical Journal .122 (6): 3466.Bibcode :2001AJ....122.3466M .doi :10.1086/323920
