“Lucky Imaging” - Sharpest pictures of Stars ever - even better than Hubble
September 7th, 2007
Feast your eyes on this Cat’s Eye: Look at the clarity of the image.
Images from ground-based telescopes are generally blurred. There are techniques to reduce the blur (adaptive optics is one of them); now add another smart processing to the list.
The technique works by recording partially corrected adaptive optics images at high speed (20 frames per second or more). Software then checks each image to sort out which are the sharpest. Many are still significantly smeared by the atmosphere, but a small percentage of them are unaffected (sometimes a portion of the image might be unaffected).
These are combined to produce the final high-resolution image that astronomers want. The technique is called “Lucky Imaging” because it depends on the chance fluctuations in the atmosphere sorting themselves out and providing a set of images that is easier for the adaptive optics system to correct.
This work was carried out on the 200-inch (5.1 meter) Hale Telescope on Palomar Mountain. Like all other ground-based telescopes, the images it normally produces are typically 10 times less detailed than those of the Hubble Space Telescope.
Palomar’s adaptive-optics system produces superb images in the infrared, but until now, its images in visible light have remained markedly poorer than Hubble images. With the new Lucky Camera, astronomers were able to obtain images that are twice as sharp as those produced by the Hubble Space Telescope—a remarkable achievement.
The images produced in the study are the sharpest direct images ever taken in visible light either from the ground or from space.
In this image of the Cat’s Eye Nebula, one can resolve filaments that are only a few light-hours across! This is so amazing, we can see 3000 light years away and resolve things that are few light hours apart!
The full adaptive system will be ready in 2010 and I can’t wait to see some spectacular pictures.
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