CATACLYSMIC VARIABLE STAR
GO COMAE BERENICES
23-25th April 2005
GO Com is an SU UMa type Cataclysmic Variable, A binary system consisting of a main sequence star orbiting a white dwarf. From time to time this system produces outbursts lasting a few days during which the magnitude increases from mag 18 to mag 13. Some of these outbursts are accompanied by superhumps, regular variations of a few tenths magnitude and around 1.5 hours period, slightly longer than the orbital period of the system. General information on Cataclysmic Variables can be found here http://www.mssl.ucl.ac.uk/www_astro/gal/Sardinia_SA.htm
An outburst was reported on 20th April 2005 and a series of observations were made during the nights of 23 and 24th April.
The VC200L telescope was used with an unfiltered B+W SC3 modified webcam. Ensemble photometric measurements were made on stacks of 20x10sec images using Teleauto software. The comparison star magnitudes were taken from AAVSO chart 1251+27 (d). (Bright moonlight and thin high cloud affected the precision) The results were averaged in threes to reduce the errors further. Each point represents approximately 11 minutes of data. The errors as estimated from the check star variablity are +-0.03mag on 23/4th and +-0.05mag on 24/5
Combining the results from the two nights, it is possible to fit a periodic curve to the variations. (The period of 0.0629 was obtained from the results of a previous super outburst of this system in June 2003)
The data appears to be a good fit, suggesting that the current outburst shows superhumps with a similar period to those seen in the 2003 outburst.
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