New observations of the eclipsing binary system NY Vir and its candidate circumbinary planets
Hüseyin Er, Aykut Özdönmez, İlham Nasıroğlu
Abstract
ABSTRACT As a result of various studies, it has been determined that several post-common envelope eclipsing binaries have variations in their orbital periods. These variations are thought to be caused by the existence of additional bodies in the system (hypothetical stars or planets) and/or other physical effects (such as angular momentum loss, magnetic activity) of the binary system. It is also known that the sdB+M eclipsing system NY Vir has shown such variations in the last decade, indicating additional objects and/or other physical effects. In this work, we present 51 new eclipse times for this system, which extend the time-span of it is O − C diagram by about 3 yr, obtained between 2015 and 2021 using two different telescopes in Turkey. The data obtained in the last 3 yr show a new trend in the O − C diagram differently from the predictions of the previous studies. Our model is consistent with the new O − C diagram, which is statistically well fitted with the quadratic term and the additional two planets with masses of M3 = 2.74 MJup and M4 = 5.59 MJup. However, the orbital period variation can also be related to magnetic activity. In order to better understand the mechanism causing the changes in the orbital period, new observation data are needed that will show at least one full cycle of the change in the O − C diagram.