view Abstract Citations (23) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A spectroscopic study of the close binary CG Cygni. Naftilan, S. A. ; Milone, E. F. Abstract Fifty spectrograms of the eclipsing close binary CG Cyg are examined. The component stars are classified as G9.5 V and K3 V, respectively. Indirect evidence for emission or circumstellar absorption of Balmer lines is discussed, each component is found to contribute Ca II H and K emission of nearly equal strength, and the Ca II emission is suggested to be of probable chromospheric origin. Respective rotation rates of about 58 and 70 km/s are obtained for the hotter and the cooler star, along with respective radii of 510,000 and 620,000 km, and a system mass ratio close to 1.0. It is concluded that the Ca II emission, variable Balmer lines, spectral types, approximate sizes, and mass ratio of this system provide a further link between the 'short-period' RS CVn-related binaries and the classical RS CVn systems. Publication: The Astronomical Journal Pub Date: August 1979 DOI: 10.1086/112531 Bibcode: 1979AJ.....84.1218N Keywords: Cygnus Constellation; Eclipsing Binary Stars; Emission Spectra; Stellar Spectra; Stellar Spectrophotometry; Balmer Series; Calcium; H Lines; K Lines; Light Curve; Spectrum Analysis; Stellar Rotation; Astrophysics; Close Binaries:Rotation; Diameters:Eclipsing Binaries; Eclipsing Binaries:Spectroscopy full text sources ADS | data products SIMBAD (1)