Jodrell Bank’s Telescopes Look to a Bright Future
After nearly 9 months of unseen activity, the University of Manchester’s
giant Lovell radio telescope at Jodrell Bank is now scanning the heavens
again, but anyone looking across the Cheshire plain may notice that it now
looks rather odd! The well known landmark is now well on the way to the
completion of a 32.4 M [pounds sterling] upgrade that will greatly enhance
its performance and keep it at the forefront of astronomical research for
many years to come.
A major part of the upgrade is the replacement of the steel panels that make
up the 250-ft diameter reflecting surface. The panels had begun to rust
badly and threatened the structural integrity of the surface. Following the
replacement of a trial section in 1999, work to replace them with galvanized
steel plates began in earnest in March of last year with the objective of
replacing half the surface area during the summer months. In fact, the fine
autumn weather allowed the work to continue until the end of October and has
enabled two thirds of the surface to be completed.
Over much of the surface, the original panel segments alternate with the new
unpainted metal panels. In the light of the dawn Sun the old panels, stained
with rust released when their neighbours were removed, look almost red in
colour and give an overall impression not unlike the Japanese flag! The
remaining third is fully resurfaced. Overall the effect is somewhat bizarre
but does not affect its present performance in any way.
The work will resume in March this year and should be completed by mid
summer 2002. Then, the task of cleaning and painting the bowl to give a
pristine white surface can begin. Each panel will then be precisely
positioned to accurately follow the required parabolic shape. This process,
using laser and holographic measurement techniques, will enable the new,
smoother, surface to be set to far higher precision than the old thus
allowing it to operate at shorter wavelengths and greatly extending the
scientific capability of the telescope.
During the latter months of 2001, the telescope was given a new drive system
that now provides sophisticated control to each of the ten motors that move
the telescope to follow radio sources across the sky. The improved
‘tracking’ capability will be required to keep the radio sources in the far
narrower ‘beam’ of the telescope when operated over its extended frequency
range.
Once completed, the reborn Lovell Telescope will immediately be able to make
an important contribution to the Jodrell Bank Observatory’s other major
instrument, the 217-km MERLIN array. This links together 7 antennas
stretching from the Welsh borders to Cambridge to build up the effect of a
giant radio telescope providing images with the same detail as the Hubble
Space Telescope. Christmas brought the news that the MERLIN array is itself
to undergo a major upgrade in performance which, when using the Lovell
Telescope, will improve its sensitivity by a factor of 30. The enhanced
instrument, to be known as e-MERLIN, will be able to probe far deeper into
the Universe, achieving in one day what would currently take 3 years of
continuous observation.
As Professor Andrew Lyne, Director of the Jodrell Bank Observatory, said:
“The combination of the upgraded Lovell Telescope and e-MERLIN will give the
Observatory two of the world’s major research instruments and keep UK
astronomers at the leading edge of astronomy well into this century.”
FURTHER INFORMATION
The images of the 76m Lovell Telescope relating to this press release can be
found at: http://www.jb.man.ac.uk/news/upgradeprogress/
Further details about the Lovell Telescope upgrade can be found at:
http://www.jb.man.ac.uk/news/newsurface/
Further details about the e-MERLIN upgrade can be found at:
http://www.jb.man.ac.uk/news/MERLIN/
The University of Manchester’s giant 76-metre (250ft) Lovell radio telescope
at Jodrell Bank is probably the most famous working scientific instrument in
the land and is widely regarded by the public as an icon of the very best
achievements of British science and technology. For over 40 years, the
telescope, still the third largest fully-steerable radio telescope in the
world, has played a major role in astronomical research due to its large
collecting area and great flexibility. Equipped with state-of-the-art
receiver systems, the telescope is now 30 times more sensitive than when it
was first built. In recent years it has played a leading role in many fields
of astronomy, including the detection and study of a new population of
pulsars and the discovery of the first gravitational lens. It is also
currently attracting great public interest through its participation in the
most sensitive search ever for signals from extra-terrestrial intelligence.
The upgrade package has four main elements, to be completed at a fraction of
the cost (at least =A330M) of building a new telescope of the same size and
comparable performance:
1) New Reflecting Surface The present surface panels are being replaced by
new galvanized steel plates. Attachment is with self tapping screws to avoid
thermal distortions of the type induced in the present surface by spot
welding. Work will continue throughout the spring and summer of 2002.
2) Precision Surface Adjustment Using modern holographic profiling
techniques, the new surface will be set to optimise the efficiency of the
telescope and so allow operation at wavelengths down to 5 cm, at least four
times shorter than at present.
3) New Telescope Control System The present drive and control system has
been replaced by state-of-the-art technology to increase the precision of
the positional control. This has involved independent control of individual
drive motors.
4)Refurbishment of the Track and Foundations Remedial work on the surface
layer of the foundations has been carried out to prevent water ingress and
the outer rail tracks on which the telescope rotates have been relaid.
BACKGROUND INFORMATION
Jodrell Bank Observatory is a part of the University of Manchester. The
current staff numbers about 100, 15 of whom are academic members of the
Physics and Astronomy Department of the University who teach undergraduate
students in the University and postgraduate students at the Observatory
itself. Generations of young scientists have been trained at Jodrell Bank,
some of whom are to be found at many of the world’s radio observatories, but
most of whom have gone into British industry (e.g. into various forms of
IT).
The Lovell Telescope Upgrade is being funded by the Joint Infrastructure
Fund (JIF) – a =A3750 million partnership for the improvement of University
research infrastructure between the Wellcome Trust, the Office of Science
and Technology and the Higher Education Funding Council for England. The
grant is being administered by the Particle Physics and astronomy research
Council (PPARC). Details can be found on the Wellcome Trust website at:
http://www.wellcome.ac.uk/en/1/biosfgjif.html
MERLIN (Multi Element Radio Linked Interferometer Network) is one of the
most powerful radio telescopes in the world. It is operated by the
University of Manchester on behalf of the Particle Physics and Astronomy
Research Council (PPARC) and is the radio astronomy cornerstone of the
United Kingdom’s astronomy programme. MERLIN is a sensitive network of 7
telescopes distributed over central England; several at and near Jodrell
Bank in Cheshire, one at Knockin near the Welsh border, one at Defford in
Worcestershire and the newest located just outside Cambridge. MERLIN
produces radio images with the same level of detail as that achieved
optically with NASA’s Hubble Space Telescope.
