New Systems Showing the Light-Time Effect

TL;DR

This study investigates period changes in two eclipsing binary systems, attributing observed variations to light-time effects caused by third bodies, and provides estimates of their orbital parameters and minimal masses.

Contribution

The paper presents new evidence of third bodies in EW Lyr and IV Cas through light-time effect analysis, including detailed orbital parameters and mass estimates.

Findings

EW Lyr has a third body with a 78-year orbit and eccentricity 0.57.

IV Cas has a third body with a 58-year orbit and zero eccentricity.

Calculated mass functions and minimal masses for the third components.

Abstract

Two Algol-type eclipsing binary systems (EW Lyr and IV Cas) have been investigated for period changes. Our study was primarily focused on the light-time effect with an alternative explanation by magnetic activity cycles. In the case of EW Lyr we have found a third body in the orbit with a period of about 78 years, an amplitude A=0.052 days and orbital eccentricity e=0.57. For IV Cas the long period is 58 years, amplitude A=0.034 days and zero eccentricity. With these results we are also able to calculate mass functions and minimal masses of these components.