Variable stars are a class of stars that change brightness over time, which happens over a consistent period of time. Cepheid variable stars have a very predictable brightness change over a very short period (on the order of a second to 100 days). By measuring the absolute brightness of a Cepheid variable star, the distance of the star away from Earth can then be calculated. These stars (which are pulsating Red Giant stars) vary in brightness by a factor of up to 100,000. This is caused by the rapid expansion and compression of the star. Since the star is changing in size, this means the Doppler Effect is occurring. The Doppler Effect of a Cepheid variable star can be determined by measuring the spectral data of the star and comparing the data to the wavelengths of known elements that stars are comprised of. This project focuses on determining the absolute brightness and the Doppler effect of several Cepheid variable stars, which will lead to a better fundamental understanding of Cepheid variable stars and our location in the galaxy, while being able to test the resolution of the equipment currently owned by the University of Wisconsin - River Physics Department.
