|Abstract : ||Semi-detached binaries are systems in which one of the components is generally considered to be filling its Roche lobe and transfers mass to its companion. Algol-type binaries belong to this subclass of interacting binaries and studying these objects gives a unique opportunity to derive the basic properties of interacting binaries. They also are important sources to study the stellar evolution as they have components in different evolutionary states. Variations in the orbital periods in Algols are caused by the mass transfer between the component stars and the mass loss from the systems. To understand these two behaviorus, long term period variation studies become a vital tool. In the current work orbital period variations of 33 Totally eclipsing Algols is being presented. Thereafter, the evolution of the systems, the characteristic nature of the circumstellar material around the primary components is reviewed and discussed.
Keywords : Semi-detached binaries – interacting binaries – stellar evolution – circumstellar material|