Reappearance of the optical flickering from the symbiotic star CH Cyg
ATel #6560; K. Stoyanov, G. Latev, G. Nikolov, R. Zamanov (Institute of Astronomy and NAO, Bulgaria), J. L. Sokoloski (Columbia University, USA)
on 9 Oct 2014; 07:26 UT
Credential Certification: R. K. Zamanov (rkz@astro.bas.bg)
Subjects: Optical, Binary, Cataclysmic Variable, Star, Variables
Optical observations in B-band reveal the reappearance of the flickering from the symbiotic star CH Cyg. On the night of 2014 August 15, we observed CH Cyg with the 60cm Cassegrain telescope of the National Astronomical Observatory Rozhen (Bulgaria) equipped with an FLI PL9000 CCD camera. During a total of 1.61 h of observations, we
detected flickering with a peak-to-peak amplitude of 0.42 mag.
During the time of the observing run, the brightness in B-band varied between 7.76 and 8.18 mag, so the average brightness of the system seems to have increased compared to the brightness during the time when the flickering was absent (see ATel #
4316).
On the night of 2014 October 1, we observed CH Cyg again in U and B bands with the same telescope for 1.5 hours.
The peak-to-peak amplitudes of the flickering in U and B bands were 0.37 and 0.28 mag respectively. The figure shows light curves from 2014 August 15 and 2014 October 1, together with a light curve from 2013 September 24, when the flickering was not detectable.
Given the orbital period of roughly 15 years (Hinkle et al. 2009, ApJ, 692, 1360), the disappearance of flickering in the past years (2010 - 2013) was likely due to an eclipse of the white dwarf. Now that the flickering is prominent, the system must be out of eclipse.
Light curves of CH Cyg
