The orbital period of the eclipsing dwarf nova CG Draconis

TL;DR

This study establishes CG Draconis as an eclipsing dwarf nova with a precise orbital period of approximately 4.5 hours, revealing its position above the period gap and characteristics of its eclipse features.

Contribution

First time measurement of CG Dra's orbital period confirming its eclipsing nature and providing detailed eclipse characteristics.

Findings

Orbital period is 0.18864 days (~4h 31m)

Eclipses are short and shallow, indicating grazing eclipses

Flickering persists during eclipse, suggesting non-occulted flickering source

Abstract

We have performed time resolved photometry on the dwarf nova CG Dra and have established for the first time that it is an eclipsing system. By measuring the times of the eclipses, we determined the orbital period as 0.18864(4) d, or 4h 31m 38 +/- 3s. This value is consistent with the shorter of two periods proposed from earlier spectroscopic studies. The orbital period places CG Dra above the period gap. The symmetrical eclipses are of short duration (FWHM 18+/-2 min, or 0.066(7) of the orbital period) and shallow (average 0.16+/-0.02 mag), suggesting a grazing eclipse which is consistent with an orbital inclination just above the critical value. Flickering persists through the eclipse which means that the flickering source is not occulted by the secondary star.