Astronomers say that they have used a new receiving system on CSIRO's Australia Telescope to make the first image at short (12-millimetre) wavelengths of Supernova 1987A, the remains of an exploded star in a nearby galaxy.

The picture marks another step in the telescope's progress to sharper eyesight. The shorter the wavelength used to make a picture, the more detail astronomers can see.

Australia Telescope images of the expanding supernova remnant at a wavelength of 3 cm

"We've proved that the system is going to work beautifully," says CSIRO's Dr Richard Manchester.

The Australia Telescope Compact Array is a set of six radio-receiving dishes near Narrabri, NSW, that work together as one world-class radio telescope to make pictures of the sky.

Originally built to handle longer radio waves, the telescope is now being upgraded to receive wavelengths of 3 and 12 millimetres. The upgrade was funded by the first round of the Commonwealth's Major National Research Facilities program, and by CSIRO.

When the upgrade is complete the telescope will be able to see three times more detail in the supernova wreckage than it could before. Only the Hubble Space Telescope will be able to do better.

Engineers from the CSIRO Australia Telescope National Facility have been working for more than three years to improve the system.

The heart of the upgrade is a chip made of the exotic material indium phosphide, designed by CSIRO engineers and fabricated by the US company TRW.

A 'before and after' image [470KB] of the exploding star, Supernova 1987a, from the Anglo-Australian Observatory. Copyright Anglo-Australian Observatory; Photograph by David Malin

Supernova 1987A was the brightest supernova since telescopes were invented four centuries ago. It has given astronomers vital clues about what happens when stars explode.

It can be seen only from the Southern Hemisphere. The Australia Telescope is the most advanced radio telescope in the south and has been tracking the supernova's remains since 1990, when the cloud of hot gas produced by the explosion began to glow with radio waves.

"In this new image we're seeing the effect of electrons that are moving at almost the speed of light," says Dr Bryan Gaensler of the Harvard- Smithsonian Center for Astrophysics, who made the picture with Dr Manchester. "The electrons gained these terrific speeds after being hit by the sonic boom travelling outwards from the supernova."