Supernova blast in Chandra sight

The violent progress of the blast wave of Supernova 1987A - the brightest supernova seen from Earth for four centuries - has been revealed by American space agency Nasa's Chandra X-ray observatory.

Images captured by the orbiting telescope gave a unique glimpse into the early stages of such a stellar explosion.

X-rays show the shock wave smashing into a ring of matter that has surrounded the distant star for thousands of years.

It is travelling at a speed of 10 million miles per hour, with gas at about 10 million degrees Celsius some way behind it.

This super-heated material has previously been invisible fromthe Earth.

The discovery has provided scientistswith great deal of new information on thisviolent event.

The Hubble space telescope was able to see little more than a series of gradually brightening hot spots as evidence of the shock wave's progress.

David Burrows, who led the analysis of the images at Pennsylvania State University in the United States, said: "With the Hubble telescope we heard the whistle from the oncoming train. Now, with the Chandra observatory, we can see the train."

The observations support the theory that the shock wave of the supernova moves ahead of debris expelled by the explosion.