Determination of parameters of W-UMa Systems II

Photoelectric lightcurves of four W UMa systems have been solved using the Wilson-Devinney computer code, modified in order to run on a medium-size minicomputer. The solutions confirm the contact hypothesis for these four systems, three of which (TW Cet, U Peg, ER Ori) turned out to be of Binnendijk's W-type (deeper minimum produced by the eclipse of the less massive star) and another one (S Ant) of A-type. A comparison with previous solutions is made, and new absolute elements are derived for ali four systems.