New Observations of the Eclipsing Binary System NY Vir and its Candidate Circumbinary Planets

TL;DR

This study presents new eclipse timing data for the NY Vir binary system, revealing a different orbital period variation trend that suggests possible additional planets or magnetic activity effects.

Contribution

It provides 51 new eclipse times for NY Vir, extending the observational baseline and proposing a model with two additional planets fitting the new data.

Findings

New eclipse timings extend the O-C diagram by three years.

Data fits a model with two additional planets of specific masses.

Orbital period variations may also be caused by magnetic activity.

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 three years, obtained between 2015 and 2021 using two different telescopes in Turkey. The data obtained in the last 3 years shows 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 $M_3=2.74 \: M_\text{Jup}$ and $M_4=5.59 \: M_\text{Jup}$. 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 is needed that will show at least one full cycle of the change in the O-C diagram.