January 19, 1996. Copyright, 1996, Graphic News. All rights reserved

JODRELL BANK FIFTY YEARS ON
By Nicholas Booth, Science Editor

LONDON, January 19, Graphic News- Fifty years ago this week, a group of scientists who had developed radar during the war gathered in a field in Cheshire to start a new direction in their work. Their aim was to adapt many of the techniques they had pioneered to look out beyond the Earth and inaugurate radio astronomy in this country. The field was close to a place called Jodrell Bank and was known Ð if at all Ð as a botanic outstation of the University of Manchester. Today it is one of the worldÕs leading research establishments and is more formally known as the Nuffield Radio Astronomy Laboratories.

Under the guidance of Sir Bernard Lovell, a large, 250 foot diameter telescope took shape in the 1950s and still dominates the flat Cheshire skyline, becoming one of the most instantly recognisable features in the county. Realisation of the project was long and arduous, but just months after its completion in 1957, the telescope was used to track the first Russian Sputnik and its future was assured. Now renamed the Lovell telescope, it is just one of the many facilities operated by University of Manchester radio astronomers.

Many of the most exciting results from Jodrell Bank in recent years have come from using a series of smaller radio telescopes located throughout the English countryside and known as MERLIN. The acronym stands for the Multi-Element Radio-Linked Interferometer Network, with interferometry being the technical name for linking telescopes together electronically to synthesise a telescope equivalent to 180 miles in diameter. As a result, the MERLIN system is capable of exquisite sensitivity and unprecedented resolution at radio wavelengths Ð providing the same resolution from the ground as the Hubble Space Telescope from orbit.

The power of MERLIN has been demonstrated time and time again. Because many astronomical objects are surrounded by dust, optical telescopes cannot see into them. Dust is opaque to radio waves, so MERLIN has seen the last gasps of dying stars and the way in which they explode into space shortly thereafter. Most recently, MERLIN has been used to look at one of the most unusual phenomena in the cosmic zoo, known as an active galaxy.

Galaxies are collections of many millions of stars. Many appear to have mysterious, very bright centres and astronomers have postulated that these are due to black holes. They are active in the sense that the black holes consume surrounding material and heat it to many thousands of degrees, spraying out a stream of highly energetic particles. It is often difficult to learn about their chemistry because the material is so hot and dense.

Using MERLIN, JodrellÕs Dr Carole Mundell and her colleagues have looked at hydrogen emitted out of a fairly nearby galaxy called NGC 4151. Appearing like a cosmic lighthouse, the Jodrell team have been able to see it much more clearly, helping to refine theories of how black holes form at the centre of galaxies.

This weekÕs conference will include a commemorative address by Sir Bernard and will review the future of radio astronomy with the technique of interferometry extended out into space with satellites, producing a radio telescope the size of the Earth.

Sources: Nuffield Radio Astronomy Laboratories