Hale-Bopp as it appeared in Early March 1997. The telescope was tracked on the motion of the comet relative to the earth. This resulted in the trailing of background stars. This technique is very much like using a still camera to pan a moving object, freezing the motion of the object, while the background blurs.
Plasma glows blue from the energy received from the sun.
Waves in the plasma result from pressure from the solar wind, and the rapid rotation of the comet's physical surface. This image also illustrates the extreme blue sensitivity of Kodak PMZ 1000 film. The dust tail to the right of the blue plasma stream should be much more yellow in appearance. Copyright 1999, Celestial Images. All rights reserved.