A team of British and American researchers working together 
has used a new imaging system to take ground-based pictures of space that for the first time rival or even exceed the clarity of Hubble telescope images.
The trick? Ordinarily, Earth-based images of stars and other stellar objects are blurry, because light passes through random fluctuations in the atmosphere before reaching the ground. The same effect that makes stars appear to twinkle to the naked eye results in smeared, or unclear photos.
In the past, astronomers have used a technique called "adaptive imaging" to correct for this blurriness, but that has been effective only with infrared pictures, limiting its use.
However, the team of astronomers from Cambridge and Caltech has pioneered a new system that promises to substantially improve the capabilities of ground-based observatories, combining an ultra-sensitive digital imaging chip (able to detect individual photons) with new adaptive imaging techniques.
The system works by taking a number of high-speed photographs – 20
frames per second or more – and then using a software tool to pick the sharpest ones, and combine elements from different frames. The hope is that chance fluctuations in the atmosphere act to cancel each other out, an effect lending the process its name of "Lucky Imaging."
The team has applied the technique to images taken from the 200 inch telescope on Mount Palomar near San Diego, with considerable success.
Researchers have already been able to pick out details of multiple star star systems that have previously been too close together to see, they said.
The photos included here depict the Cat's Eye Nebula (NGC6543), some 3000 light years distant, first using the Lucky Imaging system, then as previously recorded conventionally through the Palomar telescope. More Lucky Imaging photos can be seen on the project's Web site.
"Lucky Camera" takes sharpest ever images of stars [Press Release]
(Photo Credit: University of Cambridge/Caltech/Palomar Observatory)
