There are three available. The first is a detailed release from the Institute of astronomy in Cambridge giving detailed technical and support information. This is followed by the Caltech Press release followed by one put out by Cambridge University on the same day
British astronomers from the University of Cambridge and the California Institute of Technology (Caltech) have developed a new camera that gives much more detailed pictures of stars and nebula than even the Hubble Space Telescope, and it does all this from the ground.
Images from ground-based telescopes are invariably blurred out by the atmosphere. Astronomers have tried to develop techniques to correct the blurring called adaptive optics but so far they only work 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 which at last makes very high resolution imaging in the visible possible.
The camera works by recording the images produced by an adaptive optics front-end at high speed (20 frames per second or more). Software then checks each one to pick the sharpest ones. Many are still quite significantly smeared but a good percentage are unaffected. These are combined to produce the image that astronomers want. We call the technique "Lucky Imaging" because it depends on the chance fluctuations in the atmosphere sorting themselves out.
This work was carried out on Mount Palomar with their 200 inch (5.1 m) telescope. Like all other ground-based telescopes, the images it normally produces are typically 10 times less detailed than those of the Hubble Space Telescope. Their adaptive optic system works well in the infrared but up to now gives images in the visible that are still markedly poorer than Hubble images. With the Lucky Camera we obtain images that are twice as sharp as those produced by the Hubble Space Telescope, a remarkable achievement.
These are the sharpest images ever taken in the visible either from the ground or from space. To get sharper pictures you have to use an even bigger telescope.
It opens up the possibility of further improvements on even larger telescopes such as the 8.2 m Very Large Telescope (VLT) of the European Southern Observatory in Chile or the 10 m Keck telescopes on the top of Mauna Kea in Hawaii.
Most astronomical objects are so far away that astronomers are desperate to see more and more detail within them. Lucky Imaging techniques have already enabled the discovery of many multiple star systems which are too close together and too faint to find with any standard telescope. The pictures (attached) of the globular star cluster M13 which is at a distance of 25,000 light years are able to find stars as little as one light day apart. The nearest star to earth is over three light years away.
We can also see very fine detail in objects such as the Cat's Eye Nebula (NGC6543). It is eight times closer to earth than M13 so we can resolve filaments that are only a few light hours across.
The first picture attached here shows what an image of the centre of the globular cluster is usually like on the Palomar 200 inch telescope in the visible. All these images cover a tiny area, only 10 x 10 arcseconds, smaller than the apparent width of a human hair held at full stretch of your arm. The second shows how much more detail we see with the Lucky Camera attached to the adaptive optic system on that telescope. It is much clearer and sharper than the Hubble Space Telescope picture of the same piece of sky. The next pair of images show the same comparison, but with images of the Cat’s Eye Nebula, NGC6543. Here the green light is oxygen emission, the red is hydrogen emission, and the blue is near-infrared radiation.
There is also a small amount of video material of limited quality available.
This technique has only been possible because of a new kind of CCD camera chip developed by British company, E2V Technologies of Chelmsford (http://www.e2v.com/home.cfm ). Normally cameras have a residual noise even in the absence of light which greatly limits how faint you can see. This new camera chip is so sensitive that it can detect individual particles of light called photons even when running at high speed. It is this extraordinary sensitivity that makes these detectors so attractive for astronomers. Engineers at Cambridge University have built some of these detectors into their astronomical cameras to make the Lucky Camera work so well.
Lucky Imaging is a technique that has been developed at the Institute of Astronomy in Cambridge. There are more details and many more pictures available on the Lucky Imaging Website which may be found at: http://www.ast.cam.ac.uk/~optics/Lucky_Web_Site/index.htm
The Institute of Astronomy is a Department of the University of Cambridge (http://www.ast.cam.ac.uk/). It is one of the foremost astronomy departments in the world with an unequalled record of scientific publication. It is the home of the Astronomer Royal, President of the Royal Society and Master of Trinity College, Lord Rees of Ludlow. The work of the Institute covers a wide range of astronomical subjects from the formation of planets and stars and galaxies up to the study of the cosmic microwave background. The Director of the Institute of Astronomy is Professor George Efstathoiu.
The Palomar Observatory is owned and operated by the California Institute of Technology (Caltech). It is located in Southern California about one hour drive from San Diego at an altitude of about 5500 feet (1650 m). The Palomar 200 inch telescope was constructed before and after the Second World War and opened in the late 1940s. For many years it was the largest telescope in the world. Today the quality of its mirror is significantly poorer than those of more modern telescopes, and this made the present study even harder.
These can be found on the Caltech Astronomy website at: http://www.astro.caltech.edu/palomar/hale.html . There are lots of pictures there but do not be distracted by the ones that have a yellow beam coming out of the telescope. This is not part of the present technique -- it is another story entirely!
There are vast numbers of beautiful pictures available from: http://hubblesite.org/gallery/spacecraft/
There are a few pretty pictures of the Paranal site of the VLT, a group of four telescopes each 7.5 m in diameter in northern Chile where the VLT is situated at: http://www.eso.org/esopia/images/archive/subtopic/paranal/ . There are some images of the Keck 10 meter telescope on the summit of Mauna Kea in Hawaii at: http://www.keckobservatory.org/view_album.php?album_id=12.
In the UK and Europe please contact:
Dr Craig Mackay, Reader in Image Science
Institute of Astronomy
Cambridge CB3 0HA, UK
Tel: +44 (0)1223 337543
In the United States please contact:
Dr Nick Law, California Institute of Technology
> 1200 E. California Blvd.
Pasadena, CA 91125, USA
The Globular cluster M13 as imaged conventionally by the Palomar 200 inch telescope.
The Globular cluster M13 as imaged with the Lucky Camera behind an adaptive optics system on the Palomar 200 inch telescope.
The Cat’s Eye Nebula (NGC6543) as imaged conventionally by the Palomar 200 inch telescope. The green light is oxygen emission, the red is hydrogen emission, and the blue is near-infrared radiation.
The Cat’s Eye Nebula (NGC7543) as imaged with the Lucky Camera behind an adaptive optics system on the Palomar 200 inch telescope. Colours as above image.
For Immediate Release
September 3, 2007
PASADENA, Calif. — Astronomers from the California Institute of Technology and the University of Cambridge have developed a new camera that produces much more detailed pictures of stars and nebulae than even the Hubble Space Telescope, and it does all this from here on Earth.
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.
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. "The system performed even better than we were expecting. It was fantastic to watch the first images come in and see that we were easily doing better than Hubble," says Nicholas Law, a postdoctoral scholar at Caltech and principal investigator for the instrument.
Most astronomical objects are so far away that astronomers are desperate to see more and more detail within them. The new pictures of the globular star cluster M13, located 25,000 light years away, are sharp enough that astronomers are able to find stars as little as one light-day apart. A light-year is the distance light travels in one year (almost 6 trillion miles). A light-day is the distance light travels in just one day. Stars in the vicinity of the solar system are much farther apart –the nearest star to our solar system is over four light-years away.
The astronomers also observed very fine detail in objects such as the Cat's Eye Nebula (NGC 6543). It is eight times closer to earth than M13, allowing filaments that are only a few light-hours across to be resolved.
The use of the camera at Palomar was a demonstration of the potential of visible-light adaptive optics and offers a glimpse of the detailed imagery to come. Astronomers at Caltech and the Jet Propulsion Laboratory are currently developing the first-ever astronomical adaptive-optics system fully capable of capturing visible-light images. It will routinely allow the 200-inch telescope at Palomar to outperform the Hubble Space Telescope at even blue wavelengths. Using state-of-the-art deformable mirrors, sensors, and a powerful laser, the upgraded Palomar adaptive-optics system will provide finer correction of the atmospheric blurring than any present adaptive optics system, allowing long-exposure images with the same fine detail as the "lucky" images taken recently.
To get even sharper pictures, astronomers will need to use bigger telescopes.
The results open up the possibility of further improvements on even larger telescopes, such as the 10-meter Keck telescopes on the top of Mauna Kea in Hawaii or in the future even larger telescopes, such as the Thirty Meter Telescope (TMT).
Working on the Lucky Imaging project were Law, Dekany, Mike Ireland, and Anna Moore from Caltech and the Palomar 200-inch crew. Other team members included Craig Mackay from Cambridge, James Lloyd from Cornell University, and Peter Tuthill, Henry Woodruff, and Gordon Robertson from the University of Sydney.
Images are available at http://www.astro.caltech.edu/~nlaw/lamp_pics/ and http://www.astro.caltech.edu/palomar/AO/luckycam.html.
Nicholas Law, postdoctoral scholar
California Institute of Technology
Phone: (626)-395-2223 (US)
Craig Mackay, Reader in image science
Institute of Astronomy, University of Cambridge
Phone: +44 (0)1223 337543 (UK)
Scott Kardel, public affairs director Palomar Observatory
Phone: (760) 742-2111
Visit the Caltech Media Relations website at http://pr.caltech.edu/media.
Standard Telescope on the left with the “Lucky Camera” View on the right
A team of astronomers have taken pictures of the stars that are sharper than anything produced by the Hubble telescope, at 50 thousandths of the cost.
The researchers, from the University of Cambridge and the California Institute of Technology (Caltech), used a technique called “Lucky Imaging” to take the most detailed pictures of stars and nebulae ever produced – using a camera based on the ground.
Images from ground-based telescopes are usually blurred by the Earth’s atmosphere - the same effect that makes the stars appear to twinkle when we look at them with the naked eye.
The Cambridge/Caltech team, however, surpassed the quality of images taken from space by using a high-speed camera to take numerous images of the same stars at a rate of 20 frames per second. Because of fluctuations in the atmosphere, some of these were less smeared than others. The team then used computer software to choose the best images, and these were combined to create pictures far sharper than anything that has been taken from space.
Dr Craig Mackay, from the Institute of Astronomy at the University of Cambridge, who led the research, said: “To produce images sharper than Hubble from the ground is a remarkable achievement by anyone’s standards.
“These are the sharpest images ever taken either from the ground or from space and yet we are essentially using ‘Blue Peter’ technology. Amateur Lucky Imaging is popular because the technique is so cheap and effective. The low cost means that we could apply the process to telescopes all over the world.”
The Lucky Imaging technique was first mooted in the late 1970s and has r enabled the discovery of many multiple star systems which are too close together and too faint to find with any standard telescope.
Their pictures of the globular star cluster M13, which is 25,000 light years away, are so detailed that they were able to find stars as little as one light day apart. The images of the Cat’s Eye Nebula (pictured), were so fine that they could pick out details separated by only a few light hours.
The work was carried out on Mount Palomar, California, using the 200-inch telescope at the Palomar Observatory. Like all other ground-based telescopes, the images this produces are typically 10 times less detailed than those produced by Hubble. Using the Lucky Camera, however, it was possible to obtain images that are twice as sharp as those of the space telescope.
The technique could now be used to improve much larger telescopes such as those at the European Southern Observatory in Chile, or the Keck telescopes in the top of Mauna Kea in Hawaii. This has the potential to produce even sharper images.
“The images space telescopes produce are of extremely high quality but they are limited to the size of the telescope,” Dr Mackay added. “Our techniques can do very well when the telescope is bigger than Hubble and has intrinsically better resolution.”
For more information contact:
Tom Kirk, Communications Office, University of Cambridge, Tel: 01223 332300, mobile 07917 535815, Email: firstname.lastname@example.org
Dr Craig Mackay is happy to be contacted directly for interviews. Tel: 01223 337543, mobile 07780 994853, Email: email@example.com
Images and film taken using the Lucky Camera are also available.