There are two types of variables, binary stars and Cepheid variables
What are cepheid variables?
Cepheid variables are giant yellow stars that regularly expand and contract in size.
Graphs showing how the light intensity of a star changes over time are called light curves, you can determine the period of variability by reading of it's axis.
In a binary system, the brighter star is called the primary star and the dimmer star is called the secondary star. If the stars orbit in a plane along our line of sight, the…