Lucky Cam Adaptive Optics on the 200-inch Hale Telescope at the Palomar Observatory
The Power of Adaptive Optics enhanced by LuckyCam.
The above image shows the Cat's Eye Nebula (NGC 6543) seen in visible light using the 200-inch Hale Telescope at Palomar Observatory. This animated gif cycles between the standard visible-light view which is blurred by Earth's atmosphere and a corrected image using Palomar's Adaptive Optics System and LuckyCam.
Until now, images from ground-based telescopes have been invariably blurred by Earth's atmosphere. Astronomers have developed a technique, known as adaptive optics (AO), to correct the blurring, but so far it has only worked successfully in the infrared, where the smearing is greatly reduced. However, a new noise-free, high-speed camera has been developed at the Institute of Astronomy in Cambridge that, when used behind the infrared Palomar Adaptive Optics System, at last makes very high resolution imaging possible in ordinary visible light.
The camera 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. 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.
The 200-inch (5.1 meter) Hale Telescope, like all other ground-based telescopes, 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 of the Cat's Eye Nebula, 20 arcseconds on a side, are are a false-color combination of three wavelengths of light. The green light is mostly 500nm oxygen emission, red light from H-alpha hydrogen emission and blue color which has contributed by near-infrared (I-band) light.