Hi,
I recently came across this nice tutorial by NASA
http://encompass.gsfc.nasa.gov/caseStudies/moon.pdf , explaining a bit how the Nix and Hydra, the moons of Pluto, were discovered with the Hubble Space Telescope and some clever image processing. You can get the data from
http://archive.stsci.edu/proposal_search.php?mission=hst&id=10774 (doing it like a real scientist), or simply download it from
http://encompass.gsfc.nasa.gov/data.html. You can easily reproduce the result with PI, if you like:
- align the science frames of the *_drz*.fits files using a single point alignment on Pluto (not the stars, they are moving in the background) with DynamicAlignment
- integrate the aligned images with ImageIntegration, using Linear Fit Clipping.
The attached screenshot shows this:
- bottom left: one of the science frames as provided by Hubble. Lots of cosmics and star trails
- top right: integration without pixel rejection. Start trails still visible
- top left: ImageIntegration with pixel rejection
The two very bright spots are Pluto and Charon, the small ones to the top right of Pluto are Nix and Hydra.
Enjoy,
Georg
