PUBLICATIONS OF THE ASTRONOMICAL OBSERVATORY OF BELGRADE104, Page 87-90, https://doi.org/10.69646/aob104p087
PROCEEDINGS of the XX Serbian Astronomical Conference, Belgrade, October 16 - 20, 2023, Edited by Jelena Petrović, Dušan Marčeta and Ana Lalović
Published by: Astronomical Observatory, Volgina 7, 11060 Belgrade 38, Serbia

Abstract. Luminous red novae are rare transient events thought to be the result of the merger of contact binary system components into a single star. So far, there is only one confirmed observed event, that of V1309 Sco (Nova Sco 2008). Unfortunately, that system was recognized as a contact binary only after the merger event, so targeted observations to fully elucidate the properties of the components and events leading up to the merger itself could not be performed. With ever increasing number of identified contact binary systems from sky surveys there is heightened interest in the identification of red nova progenitors. We have developed and are refining methods and relationships linking geometric parameters obtained through light curve analysis and the mass of the primary component with orbital instability. We discuss some theoretical and practical application of the new relationships to a group of poorly studied contact binary systems. In addition, we briefly touch on the effects of stellar composition on contact binary orbital stability.