The evolution of the eccentricity in the eclipsing binary system AS Camelopardalis

TL;DR

This study analyzes over 50 years of photometric data of the eclipsing binary AS Cam, revealing a change in eccentricity possibly caused by a third companion affecting the system's orbital dynamics.

Contribution

It provides new photometric elements and evidence of eccentricity evolution, suggesting the presence of a third body influencing the binary's orbit.

Findings

Eccentricity changed by Δe=0.03 ± 0.01 over 50 years

Evidence of a third companion affecting orbital motion

Discrepancy between observed and theoretical apsidal motion rates

Abstract

In 2002, 2004, and 2017 we conducted high precision CCD photometry observations of the eclipsing binary system AS~Cam. By the analysis of the light curves from 1967 to 2017 (our data + data from the literature) we obtained photometric elements of the system and found the change of the system's orbital eccentricity by $\Delta e=0.03 \pm 0.01$. This change can indicate that there is a third companion in the system in a highly inclined orbit with respect to the orbital plane of the central binary, and its gravitational influence may cause the discrepancy between the observed and theoretical apsidal motion rates of AS~Cam.