Detailed analysis of an eccentric TESS binary star with solar-type components: TIC 284613090

Abstract

Eclipsing binary stars are significant objects for understanding stellar evolution, stellar population synthesis, and galaxy dynamics. Thanks to the increasing number of high-quality photometric data of space observations, the sensitivity of the fundamental astrophysical parameters (mass M, radius R) has risen and this situation has highlighted the importance of eclipsing binary stars once again. There are known relations between M and luminosity (L) for the eclipsing binary systems, especially for the detached binaries. However, in these M−L relations, some break-points appear and those points need to be re-examined with accurate M and L parameters of stars located at these areas. One of these break-points presents around the Solar mass. Therefore, this study focuses on a TESS field object TIC 284613090 which is an eccentric binary system containing two solar-type components. In the study, the fundamental parameters of the binary component stars were precisely obtained by a simultaneous analysis of the radial velocities and the TESS light curve. As a result, the masses and radii of the primary and secondary binary components were found to be M1=1.030 (8) M⊙, M2=1.019 (8) M⊙ and R1=1.611 (5)R⊙, R2=1.485 (5) R⊙, respectively. When the evolutionary status of the component stars was examined, it turned out that they are approaching the end of their main sequence evolution and the age of the system is 9.65 (20) Gyr. As a result of binary evolutionary models, it was also found that TIC 284613090 started its evolution with an orbital period of 11.83 days and an eccentric orbit with a value of e = 0.227. The position of the binary components in the M−L relation was examined as well and showed consistency with the relation.