Comet Schwassmann-Wachmann 1 (29P/Schwassmann-Wachmann 1)

A periodic comet, discovered from Hamburg in 1927. It is in an almost circular orbit with a period of 16.1 years, which keeps it permanently between Jupiter and Saturn. It can be seen each year at the time of opposition. Though it is usually of eighteenth magnitude, it can brighten by as much as 4-8 magnitudes in a few days. The outbursts are accompanied by changes in the nucleus and coma.