GSC 5206:1013

GSC 5206:1013 is a 15th magnitude star in the constellation Aquarius. I discovered it to be variable in October 2012 while analysing images taken for asteroid photometry. At the time, it looked like it was just another W UMa type eclipsing variable, so I assignment it to a student as a project to determine the period and to model the system.

However, as we obtained more observations, the system turned out to be far more complex than we thought! It certainly was an eclipsing binary with a period of about 7.01 hours. However superimposed on this was another variation with a period of about 34 days. More recent observations have shown that there are 2 stars separated by about 3.3 arc seconds. High resolution photometry on each star showed that they were BOTH W UMa stars!!! Their periods differed by just a few minutes and this gave a "beat" period of a little elss than 34 days. This system is now under extended scrutiny and we are endevouring to obtain some spectroscopy to try and work out just what is going on with this star.

Initial lightcurve results for GSC 0540:1013.

The above plot shows the initial results for GSC 5206:1013. As can be seen, there was some sort of period at about 7 hours, but the lightcurve was a mess!

The next plot shows the raw measurements for GSC 5206:1013. Now there appears to be a longer period of about 18 days, that is superimposed in the 7 hour period.

Raw photometry results for GSC 0540:1013.

The next 2 plots shows the latest measurements for each star. As can be clearly seen, each star is a W UMa variable. Their periods differ by about 3.7 minutes, resulting in the origional confused lightcurve.

Lightcurve results for GSC 0540:1013, star A.

RLightcurve results for GSC 0540:1013, star B.