This is an animation of Comet 1999S4 Linear.
Each of the fifteen images is a 20 second exposure using taken with an SBIG st6 ccd camera mounted on the JMI 18" NGT at the Space Studies Planetary Sciences Observatory.
The entire movie covers about 20 minutes starting at 12:02AM, July 22, 2000.
In this time the comet moves about 5.5 arcminutes.