X-ray Observations of RV Tau Variable Stars

RV Tau variable stars are pulsating Cepheid Type II variables often found in binary systems surrounded by circumbinary and circumstellar disks. The frequency and characteristics of X-ray emission from RV Tau variables stars are unknown and determining their X-ray properties can open new windows into the late stages of binary evolution. Prior to 2022, only one RV Tau variable star, U Monocerotis, had been targeted by a modern X-ray observatory (XMM-Newton). The detected X-ray emission was surprising and difficult to understand. The hot plasma is likely due to shocked gas possibly caused to accretion events related to the orbital motions within the large circumbinary disk. We present our latest efforts to detect and classify X-ray emission from additional RV Tau variable stars, including the results of new targeted and serendipitous observations of these variable stars.