One more quot;wrinklequot; in all this. All pulsations we have discussed are radial. What if there are non-radial pulsations present?

One more "wrinkle" in all this. All pulsations we have discussed are radial. What if there are non-radial pulsations present? Two periods, one short (less than a day) one long (months) superimposed. It is just like adding sine waves of different frequency. Binary systems are common. What if two stars get too close together? Binary systems are common. What if two stars get too close together?