An Audit of the Light Curves of RV Tau Variable Stars in the ASAS-SN Database

Abstract: RV Tauri variable stars are pulsating evolved stars that are identified by a characterizing feature in their light curves: alternating deep and shallow minima. Many RV Tauri variable stars were originally classified decades ago using visual observations and photographic plates. However, recent studies suggest that there are imposters, or misclassified variables, amongst the sample of RV Tau stars. In this study, we examine 84 known and suspected RV Tau stars that appear in the variable star catalog of the All Sky Automated Survey for Supernova (ASAS-SN). For each ASAS-SN light curve, we performed a period analysis and compared our results with those of the General Catalog of Variables Stars (GCVS) and the automatic classification algorithm used by ASAS-SN. We found that the pattern of alternating minima present in RV Tau variable stars often confuses automatic classification. Our results include updated periods and classifications for our sample. Our study provides an important step towards obtaining a robust sample of RV Tau variable stars to better understand the pulsation mechanism and the evolutionary pathway of these variable stars.