Space Astronomy Laboratory
ASTRO - 2
WUPPE PROGRAM CLASS 3.2
CATACLYSMIC VARIABLE STARS
Object: Z Camelopardalis (Z-CAM)
ID # 3213
UW Astronomer: Joni Johnson
Z-Cam is a dwarf nova star in the constellation of the Camelopardalis. As a variable star, it ranges between 10th and 14th magnitude; it's 2- to 3-week internal explosions resemble small-scale nova outbursts. Z-Cam can remain constant for several months at a time, but it also goes through erratic periods of outburst which have no pattern.
A variable star is one that changes its brightness. There are several classes of variable stars, including "periodic" variables (which change their brightnesses on a regular schedule, ranging from hours to many years) and "irregular" variables (which abide by no fixed schedule). Careful, long-term monitoring of variable stars in one major way in which amateur astronomers have made important contributions to research astronomy. An important class of variable stars, useful for measuring distances, is called Cepheids (because the first one discovered happened to lie in the constellation of Cepheus).