This week we look at the light curve of the variable star GQ Mon. It is situated in the NGC2264 target region and classified as a T Tauri star.
We have now nine observing seasons worth of data – but only show the V, R, and I-band data for the last winter in the above plot. The longer term light curve shows that the baseline brightness of the star can vary from season to season by about one magnitude. Additionally, in most of the seasons there are dimming events of variable duration and depth. These can reach up to 2mag in brightness decrease.
In the detailed plot above we can see that this general behaviour is also occurring during the last winter. There are longer (~2weeks) and shorter (~few days) dimming events of varying depth. In addition there are day to day variations of the order of ten to twenty percent (0.1-0.2mag). These tend to be correlated in the various filters and are hence real variations and not noise in the photometry.