A Refined Orbital Ephemeris for the Intermediate Polar FO Aquarii and Evidence for a Period Derivative
Peter Garnavich (Notre Dame), Jordan Tweddale (Notre Dame), Colin Littlefield (BAERI)
arXiv:2509.22786v1 Announce Type: new
Abstract: We combine more than 40 years of eclipse timings of the intermediate polar FO Aqr and derive new orbital ephemerides. The eclipse times are best fit with a second order polynomial, implying an $8sigma$ detection of a period derivative. The results show that the orbital period of FO Aqr is currently increasing, with a derivative of $dot{P}=6.65pm0.81times10^{-11}$.arXiv:2509.22786v1 Announce Type: new
Abstract: We combine more than 40 years of eclipse timings of the intermediate polar FO Aqr and derive new orbital ephemerides. The eclipse times are best fit with a second order polynomial, implying an $8sigma$ detection of a period derivative. The results show that the orbital period of FO Aqr is currently increasing, with a derivative of $dot{P}=6.65pm0.81times10^{-11}$.