AAVSO: American Association of Variable Star Observers

The Galactic Plane Exoplanet Survey (GPX)—an Amateur Designed Transiting Exoplanet Wide-Field Search (Abstract)

Volume 45 number 1 (2017)

Paul Benni
3 Concetta Circle, Acton, MA 01720; pbenni@verizon.net


(Abstract only) GPX is designed to search high density star fields where other surveys, such as WASP, HATNet, XO, and KELT would find challenging due to blending of transit like events. Using readily available amateur equipment, a survey telescope (Celestron RASA, 279 mm f/2.2, based in Acton, Massachusetts) was configured first with a SBIG ST-8300M camera then later upgraded to an FLI ML16200 camera and tested under different sampling scenarios with multiple image fields to obtain a 9- to 11-minute cadence per field. The resultant image resolution of GPX is about 2 arcsec/pixel compared to 13.7–23 arcsec/pixel of the aforementioned surveys and the future TESS space telescope exoplanet survey. GPX is based on the Kourovka Planet Search (KPS) prototype survey and uses K-pipe data reduction pipeline. K-pipe performs all steps of the data handling from basic photometric reduction of the FITS files to the search of the transit-like events in the photometric time-series. K-pipe consists of several sequential scripts for astrometry (Astrometry.net), photometry (IRAF), and Box-fitting Least Squares transit search, and runs on a linux based laptop computer potentially operable by advanced amateurs. One Hot Jupiter was discovered with the RASA telescope and validated by RV measurements from SOPHIE spectrograph in the frames of KPS prototype survey (publication pending). Several more GPX exoplanet candidate stars of magnitude 11–13 have been identified with some showing achromatic transit events, a sign of a possible Hot Jupiter, and are now awaiting RV follow-up. This survey demonstrates that advanced amateurs can operate star survey equipment, and with professional help with follow-up and validation, expanded ground based surveys can be conducted in star fields that are challenging for other surveys.