This creates a shooting star. Throbbing Stars A throbbing or pulstating star will change its brightness because it is changing in size. This means because everything in the star is not quite balanced. The forces of gravity causes the star to get smaller. As it does so the centre is squeezed tighter and it gets hotter.
More heat is made from the nuclear furnace.
This heat cannot get out quickly enough so the outer layers of the star expands. As a result of this changing some stars actually change their brightness over the same range of time. Many stars seem to come in pairs, like twins. Some stars even come in triplets or quadruplets. Even though these twin or triplets were formed at the same time, they're often very different.