AAVSO: American Association of Variable Star Observers

´╗┐Automated Data Reduction at a Small College Observatory

Volume 47 number 2 (2019)

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Donald A. Smith
Physics Department, Guilford College, 5800 W. Friendly Avenue, Greensboro, NC 27410; dsmith4@guilford.edu
Hollis B. Akins
Physics Department, Grinnell College, 1116 Eighth Avenue, Grinnell, IA 50112

Abstract

We report on our success in automating the data analysis processes for a small (half-meter class) reflecting telescope at Guilford College, a small liberal arts college in an urban location. We give a detailed description of the hardware that makes up the instrument. We use commercial software to run the telescope, and we have written Python scripts to automatically carry out the daily tasks of image reduction, source extraction, and photometric calibration of the instrumental magnitudes to the AAVSO APASS catalogue. We characterize the effect of light pollution in terms of sky brightness and typical limiting magnitudes (V ~ 15 for a 60-s image), and we report that our RMS scatter in light curves for constant sources approaches 0.5% for bright (V < 10) sources. As a test of our system, we monitored two known variable stars, and we confirm the predicted ephemerides as given by the AAVSO web site target tool. We hope that this paper will provide a context in which future observations reported from this site can be interpreted.