Nebulae & Clusters
Variable stars are stars which exhibit changes in brightness or magnitude. Variable stars, or "variables' come in several flavors.
Pick one of the Variable Stars from the list below to see the light curves that the author has been generating for these objects.
The Cataclysmic Variable
One of the variable stars that I follow is the Cataclysmic Variable [CV]. This is a white dwarf star which is being closely orbited by a larger, red dwarf star. As the white dwarf steals matter from the red dwarf, a large amount of energy, in the form of light, is emitted. The total orbit time of the red dwarf may be from a few dozen to several hundred minutes.
The Eclipsing Binary
Other good references links for Variable Stars are:
The American Association for Variable Star Observers [AAVSO] http://www.aavso.org
VSnet in Japan http://www.kusastro.kyoto-u.ac.jp/vsnet/DNe/wzsge01.html
Gianluca Masi, Ceccano (FR) Italy http://www.eurolink.it/comets/wzsge.htm
The Beginner's Guide to Cataclysmic Variables
Catalogue of Cataclysmic Binaries, Low-Mass X-Ray Binaries and Related Objects