Northern Illinois University
Department of Physics
College of Liberal Arts and Sciences

A variable star is a star whose luminosity changes with time. Some variables are quite erratic, and others are fairly regular in their variance. For this project, we will concentrate on stars that have regular intervals. The study will center primarly on well known variables and will make use of the CCD's photometer to measure the luminosity of the star. With luck, the variance should be visible.

Procedure

The observatory system manager can give you a list of variable stars observable during a particular time of year. You will need to obtain a number of measurements during the semester (three is good) and compare the brightness of the stars observed on any given to each other. Then see if the relative brightness changed from one day's measurement to another. Explain why a star's brightness might change.