Star in the constellation Cygnus
47 Cygni Observation dataEpoch J2000 Equinox J2000 Constellation Cygnus Right ascension 20h 33m 54.18809s [ 2] Declination +35° 15′ 03.0390″[ 2] Apparent magnitude (V)4.61[ 3] (4.84 + 7.30) [ 4] Characteristics Spectral type K6: Ib + B2.5: [ 3] B−Vcolor index ± 0.023[ 5] Variable type Lc [ 6] Astrometry Radial velocity (Rv )± 0.3[ 7] km/s Proper motion (μ)RA: −6.12mas /yr [ 2] Dec.: −4.166mas /yr [ 2] Parallax (π)0.8792± 0.196 mas [ 2] Distance +965 ly +296 pc )[ 8] Absolute magnitude (MV )−4.1(−4 + −1.5) [ 3] Orbit [ 9] Period (P)± 11 dEccentricity (e)0.00 (assumed) Periastron epoch (T)± 10 JD Semi-amplitude 1 )± 0.1Details 47 Cyg Aa Mass ± 0.2[ 10] ± 3.9[ 11] M ☉ Radius 601[ 12] R ☉ Surface gravity (log g )1.23[ 13] cgs Temperature 4,217[ 13] K Metallicity [Fe/H] 0.13[ 13] dex Age ± 0.6[ 10] Myr 47 Cyg Ab Mass 0.57[ 14] M ☉ 47 Cyg B Mass 10.96[ 14] M ☉ Other designations 47 Cyg ,V2125 Cyg ,BD +34°4079GC 28630HD 196093/196094HIP 101474HR 7866SAO 70203WDS J20339+35152MASS J20335419+3515031[ 15] Database references SIMBAD data
47 Cygni is atriple star [ 4] [ 16] constellation ofCygnus , and is located aroundlight years apparent visual magnitude of 4.61.[ 3] radial velocity of[ 7]
The dual nature of this system was recognized byAnnie Cannon in 1912, and she assigned the pair separateHenry Draper Catalogue identifiers.[ 9] [ 14] spectroscopic binary in a near circular orbit with aperiod of around 3.06 yr. Thea sini value for the primary is 30.8 ± 1.6 Gm (0.206 ± 0.011 AU ), wherea is thesemimajor axis andi is theorbital inclination . It has been repeatedly resolved byspeckle interferometery since 1973. Radio emission was detected from this system in 1985/86.[ 9]
The supergiant primary is aslow irregular variable with an amplitude of about 0.1 magnitudes.[ 6] angular diameter has been measured at± 0.017 milliarcseconds usinginterferometry by theNavy Precision Optical Interferometer .[ 17] parsecs ,[ 8] R ☉ [ 12] mass of the Sun .[ 14] B-type main-sequence star , but still 2.5 magnitudes fainter than the primary.[ 4]
^ "/ftp/cats/more/HIP/cdroms/cats" .Centre de Données astronomiques de Strasbourg . Strasbourg astronomical Data Center. RetrievedOctober 15, 2022 .^a b c d Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c d Ginestet, N.; Carquillat, J. M. (December 2002)."Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components" .The Astrophysical Journal Supplement Series .143 (2):513– 537.Bibcode :2002ApJS..143..513G .doi :10.1086/342942 ^a b c Eggleton, P. P.; Tokovinin, A. A. (September 2008)."A catalogue of multiplicity among bright stellar systems" .Monthly Notices of the Royal Astronomical Society .389 (2):869– 879.arXiv :0806.2878 Bibcode :2008MNRAS.389..869E .doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation".Astronomy Letters .38 (5): 331.arXiv :1108.4971 Bibcode :2012AstL...38..331A .doi :10.1134/S1063773712050015 .S2CID 119257644 . ^a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S .1 .Bibcode :2009yCat....102025S . ^a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system".Astronomy Letters .32 (11):759– 771.arXiv :1606.08053 Bibcode :2006AstL...32..759G .doi :10.1134/S1063773706110065 .S2CID 119231169 . ^a b Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Demleitner, M.; Andrae, R. (March 1, 2021)."Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3" .The Astronomical Journal .161 (3): 147.arXiv :2012.05220 Bibcode :2021AJ....161..147B .doi :10.3847/1538-3881/abd806 ISSN 0004-6256 . Gaia eDR3 source for this star.^a b c Griffin, R. F. (June 1992). "Spectroscopic binary orbits from photoelectric radial velocities. Paper 104: 47 Cygni".The Observatory .112 :111– 120.Bibcode :1992Obs...112..111G . ^a b Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011)."A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun" .Monthly Notices of the Royal Astronomical Society .410 (1):190– 200.arXiv :1007.4883 Bibcode :2011MNRAS.410..190T .doi :10.1111/j.1365-2966.2010.17434.x S2CID 118629873 . ^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (January 1, 2022). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs".Astronomy and Astrophysics .657 : A7.arXiv :2109.10912 Bibcode :2022A&A...657A...7K .doi :10.1051/0004-6361/202142146 .ISSN 0004-6361 . 47 Cygni's database entry atVizieR .^a b Lang, Kenneth R. (2006),Astrophysical formulae Birkhäuser ,ISBN 3-540-29692-1 * ) is given by:2 ⋅ R ∗ = ( 10 − 3 ⋅ 1 , 249 ⋅ 4.472 ) AU 0.0046491 AU / R ⨀ 1 , 201.4 ⋅ R ⨀ {\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(10^{-3}\cdot 1,249\cdot 4.472)\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&1,201.4\cdot R_{\bigodot }\end{aligned}}} ^a b c Soubiran, Caroline; et al. (2016). "The PASTEL catalogue: 2016 version".Astronomy and Astrophysics .591 : A118.arXiv :1605.07384 Bibcode :2016A&A...591A.118S .doi :10.1051/0004-6361/201628497 .S2CID 119258214 . ^a b c d Tokovinin, A. (2008)."Comparative statistics and origin of triple and quadruple stars" .Monthly Notices of the Royal Astronomical Society .389 (2):925– 938.arXiv :0806.3263 Bibcode :2008MNRAS.389..925T .doi :10.1111/j.1365-2966.2008.13613.x S2CID 16452670 . ^ "47 Cyg" .SIMBAD Centre de données astronomiques de Strasbourg . RetrievedJanuary 14, 2019 .^ Mason, Brian D.; et al. (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 ^ Baines, Ellyn K.; Clark III, James H.; Schmitt, Henrique R.; Stone, Jordan M.; von Braun, Kaspar (December 1, 2023)."33 New Stellar Angular Diameters from the NPOI, and Nearly 180 NPOI Diameters as an Ensemble" .The Astronomical Journal .166 (6): 268.arXiv :2505.23514 Bibcode :2023AJ....166..268B .doi :10.3847/1538-3881/ad08be ISSN 0004-6256 .
