Period Variations and Possible Third Components in the Eclipsing Binaries AH Tauri and ZZ Cassiopeiae

D. E. Tvardovskyi, V. I. Marsakova, I. L. Andronov +1

We investigated two variable stars AH Tau and ZZ Cas. They are eclipsing binaries of W UMa and $\beta$ Lyr types. The period changes with time. The reason for steady changes of the per…