Study of eccentric eclipsing binaries provides new information about the structure and evolution of stars. Analysis of the apsidal motion (i.e., the rotation of the line of apsides) yields the so‑called internal structure constant, an important parameter in all current stellar models. Apsidal motion also has a relativistic component, which therefore allows tests of the laws of general relativity outside the Solar System. In eccentric binaries we quite often find a third component whose influence on the eclipses can be separated in the O–C diagram.

The aim of the observations is to monitor the eclipses of known eccentric binaries and, by combining data over a longer time span, to derive or refine the period of the apsidal motion.

Data added to the project will be evaluated annually and analyses of selected systems will be published in a professional journal. Observers will be able to become co‑authors of the publications.

Primary investigator: Marek Wolf, Charles University Prague, MarekWolf@seznam.cz

Project organiser: Filip Walter, Czech Astronomical Society, walter@planetum.cz

Local contacts:

CZECHIA: Filip Walter, Czech Astronomical Society, walter@planetum.cz