Here’s another great example of material I receive as Photo Editor of Astronomy. Astroimager Robert Lockwood from San Diego created an animation he did of Comet C/2007 N3 (Lulin).
For the final animation, Robert combined 75 exposures — 25 each through red, green, and blue filters. Each exposure lasted 45 seconds. He also allowed an additional 30 seconds to elapse between sets of three.
The telescope Robert used was a 7.2-inch Takahashi Epsilon-180 hyperbolic astrograph at f/2.8. His camera was a Santa Barbara Instrument Group ST-10XME, and he used Astrodon E-Series filters.
The final result shows the comet traveling against the background stars for 2 hours, 35 minutes. Nice going, Robert!
See more Comet Lulin images in our Online Reader Gallery.