Reply To: CG Dra: a VSS campaign

Forums Variable Stars CG Dra: a VSS campaign Reply To: CG Dra: a VSS campaign

Maxim Usatov

This is 24th eclipse of CG Dra observed at quiescent state. Good quality data with check star sigma = 0.04 despite being pretty dim. A hole near the start of the session was due to the ACP observatory crash, for some reason the software just dies in the middle sometimes with nothing in the logs.

Flickering is on the order of 0.01 mag, characteristic for the system, continuing into the minima and present on the whole duration of the curve tonight.

The bright spot rotates into view raising the magnitude from ~ 16.82 to 16.72 peak, amplitude of ~ 0.1 mag. The bright spot contributes approximately 10% of the total luminosity of the system.

The eclipse is V-shaped, likely due to the presence of flickering at the minimum. Ignoring the flickering, I think the minimum can be placed at 17.02 mag. The shape is asymmetric due to the bright spot, hence, the eclipse is of type V/N/A which is the second of this type observed at quiescence. This is expected.

There is an unusual 0.16 mag increase of flux on the egress, followed by a sudden drop to the expected curve.