Michael Kohl Highschool of Wald ZH, CH-8637 Laupen ZH, Switzerland
Abstract
Photographs of TV Cas and U Cep taken by students equipped with
conventional cameras and mobile, self-made mountings are used to introduce
variable stars and, in particular, eclipsing binaries. The first step--by making a
simple visual comparison--is to discover that variable stars do exist. The star's
brightness change is then estimated by visual comparison with surrounding stars
and measured by means of digitized photographs. Plots of luminosity versus time
produce a light curve that can be discussed in terms of the star's regularity and
periodicity.