The biggest digital camera ever installed on a telescope has begun work, taking spectacular and scientifically rich images of the Universe.
By Dr David Whitehouse
BBC News Online science editor
The camera, called MegaPrime, has been placed on the aging Canada-France-Hawaii Telescope (CFHT) on the summit of Mauna Kea in Hawaii, US, restoring the facility once again to the forefront of optical astronomy.
MegaPrime's view of the Rosette Nebula
The CFHT was once considered a large telescope with its 3.6-metre mirror, but today is small compared with current eight to 10-metre telescopes. But with MegaPrime installed, it is once again in high demand.
MegaPrime has a resolution of 340 megapixels. It has an unusually large field of view of one square degree, the size of four full Moons.
Surveying the Universe
At the heart of the device is a unique camera built by French engineers using British light detectors constructed by e2vtechnologies.
The light detectors - CCD (charged coupled devices) - have to be kept cold to optimise their sensitivity. They have also to be kept in a vacuum to minimise outside influences that might affect the quality of the images. Forty CCDs are combined to produce MegaPrime.
With MegaPrime, astronomers do not even have to visit the telescope to obtain their images. Requests for observations are made over the internet and the images sent to researchers when complete.
The heart of the camera
The camera will be operated for between 15 and 18 days a month when interfering moonlight is not a problem.
In its first few weeks of operation, MegaPrime participated in the discovery of new satellites of Jupiter, spied on near-Earth objects and checked wide areas of the sky to be observed on a future space mission.
It has also started the CFHT Legacy Survey which will comprise 500 nights over the next five years for studying the Kuiper Belt and the large scale structures of the Universe.