Factors that Affect Observations

Abstract

Amateur astronomers can observe Saturn regularly, contribute data that are useful to science, and at the same time thoroughly enjoy the experience. Ideally, visual and photographic observations of Saturn and its satellites should be carried out systematically throughout any given apparition, starting early in the observing season after the planet has just emerged from the solar glare after conjunction, then continuing until Saturn again enters the domain of the sun at conjunction. The synodic period (i.e., the time between two successive conjunctions of a planet with the sun) for Saturn is roughly 378^d in length, so in the course of an apparition (which lasts longer by a few days than 1 year on Earth), it will be well placed for observation for about 9 or 10 months (depending on the observer’s latitude). Widely spaced observations are of limited value, and the importance of systematic observations by many individuals, all using standardized methods, cannot be stressed strongly enough. Visual observers especially should aspire to achieve the highest possible incidence of objectivity in their data, a feat that can be accomplished when a team of individuals participates in simultaneous observations to monitor variable activity on Saturn. Of course, methods of gathering data by amateur astronomers are rapidly evolving, and it is not unusual to find modern Saturn observers employing electronic devices to supplement routine visual observations. For example, quantitative observations using photoelectric photometers are increasing in number, and the professional-type results some amateurs have been able to achieve using CCD and video imaging techniques is truly remarkable. We will discuss more about photography and CCD imaging later in this book.