Astronomy is an observational science. Its primary goal is to collect, catalog, and interpret data in a systematic manner. Much of it involves big science projects costing tens of millions of dollars annually, yet few realize that some of the most significant research arrives nearly free of charge. Given the enormous quantity of astronomical objects that require long-term study, and the limited number of professional observatories available to pursue them, dedicated individuals routinely contribute valuable data to many areas of basic research.
Through professionally sponsored programs that often involve the efforts of many observers, students can record the activity of variable stars, the behavior of the Sun’s magnetic cycle, the positions of comets and supernova, and measurements of objects that lie in the asteroid belt or travel near the Earth.
As with many advances in recent years, some of the most important involve electronics. Using a camera called a charge-coupled device, or CCD, images can be recorded through the telescope, analyzed on a computer, and stored for later retrieval. Over the course of several months, for example, while one group of students monitors a supernova as it brightens and fades, another group can study the appearance of a comet, or record the light curve of a variable star, continuing the work of students who have graduated and gone on to college.