The changing light curves of CG Cygni.
Abstract
UBV photoelectric light curves of the eclipsing close binary CG Cyg, obtained in the period from 1965 through 1977, are reduced and analyzed. Positive evidence is found for: (1) an increase in mean light by about 14% in V since 1965; (2) a sinusoidal distortion wave sweeping through the light curve, currently at an increasing rate; and (3) another change in period, probably continuous, since the late 1960s. It is shown that the distortion has a significantly variable amplitude and (with marginal significance) is greater for shorter wavelengths, on the average. It is concluded that these results, combined with a large apparent IR excess and variation in the Ca II H and K lines, may indicate a major episode in the evolution of CG Cyg.
- Publication:
-
The Astronomical Journal
- Pub Date:
- March 1979
- DOI:
- 10.1086/112436
- Bibcode:
- 1979AJ.....84..417M
- Keywords:
-
- Cygnus Constellation;
- Eclipsing Binary Stars;
- Electrophotometry;
- Light Curve;
- Stellar Spectrophotometry;
- Fourier Analysis;
- Ubv Spectra;
- Astronomy;
- Eclipsing Binaries:Light Curves;
- Eclipsing Binaries:Period Changes