RR Draconis: An Algol-Type Eclipsing Binary with a Possible Massive Tertiary Companion

In this study, we present spectoscopic observations of the eclipsing binary RR Dra carried out with our recently installed T80 telescope in Ankara University Kreiken Observatory and analyze the first radial velocity time series of this system. We simultaneously model TESS light curves along with our radial velocity data to derive absolute parameters of RR Dra system. Additionally, we investigate the period variation of the system using all the available eclipse timings in the literature. In this context, we discuss two possible explanations for the cyclic nature of the eclipse timings: i) light-time effect that corresponds to a high-mass but unseen additional component, ii) magnetic activity of the cooler component. The secular period increase in eclipse timings of RR Dra may be a combination of mass transfer and angular momentum loss, amplified by the presence of circumstellar material.