Search for transiting exoplanets in globular clusters

Abstract: This project consists of a transit search in the Messier 3 Globular cluster with the goal to assess the difficulties of observing planetary transits in globular clusters. M3 was observed for a short period of time and by performing PSF fitting, flux measurements could be done to extract light curves of the 290 stars that are included in this project. To determine the stellar type, an HR-diagram was done by observing the cluster with a g and r filter on the telescope. The results confirmed the hypothesis that the center of the cluster is too crowded so that no light curves could be extracted. However, at some distance from the center, a transiting Hot Jupiter with radius 1R_J could be readily visible around 90% of the Main Sequence stars in the cluster. At this distance from the center, reliable light curves could be extracted around other types of stars as well. However, due to the big stellar radius of the Subgiant and Giant stars compared to the planetary radius, the transit depth was too small in order to be readily visible in the light curves due to noise. My result points towards an absence of exoplanets in Globular Clusters. This is because the results show a lot of stars where a planetary transit would be easy to detect, thus they could have been detected in previous transit searches done by researchers that had more time and used a better observational setup.