Comet Hartley 2 is a periodic comet that orbits the Sun about once every 6 years. It is a relatively small comet, but during the fall of 2010, it is passing relatively close to the Earth, and it can be seen with binoculars or a small telescope.

The main image here, which combines 6 exposures taken over a period of about 10 minutes, shows the comet's rapid movement against the stellar background. The images were stacked to keep the comet centered, so the stars are trailed.

The rollover image was made from the same six exposures, using some image processing tricks to make the comet appear stationary against the background stars. One image kept the stars in the background aligned, whereas a second suppressed the star images and kept the comet aligned. These two images were then superimposed to make the final picture.

Image details: Six 90-second exposures at ISO 1600, taken with a Canon 400D camera through a Meade 12” telescope at f/6.8. 

October 2, 2010