Sheliak is a complex system consisting of a multiple star with at least two further loosely associated stars following a similar trajectory through space. The main system has several components, but most important among these are an eclipsing binary pair of bluestars that interact with one another, as mass is transferred from one of the stars to the other by gravitational effects.
At the heart of the Sheliak system, a pair of two bluestarsorbit one other in a period of about twelve days. As they pass across one another, as seen from Earth, they cause Sheliak's brightness to vary widely, by almost a full magnitude.