| 11th of December 2020 |
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| The first radio-astronomy in WA! |
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Last month, an ADAP described what may have been
the earliest radio astronomy observation in WA,
identifying some VLBI observations in November 1988.
There is nothing like making a bold claim in the public domain to unearth the true story – and so it came to pass!
Historian Harry Wendt saw the ADAP and knew better: just like
the earliest radio astronomy observations in the
eastern states
(at Collaroy Plateau in Sydney on 3 October 1945),
the first radio astronomy observations in WA were of the Sun.
Former optical astronomer Sydney Williams was a lecturer in physics at the University of Western Australia (UWA) when he became inspired by the radar-based solar research being done by CSIRO Radiophysics in Sydney. He installed a Yagi antenna on the roof of one of the UWA buildings in April 1946 and, with three honours students rounding out his team, spent the next two years using it to study solar emissions. Although little known today, the UWA group published a third of the papers on this topic during this busy time for Australian solar physics. The group did a lot of work correlating optical observations of solar flares with the radio bursts with radio fade-outs and was cited by Ruby Payne-Scott (of the Collaroy Plateau team) and Paul Wild (who established the Culgoora heliograph) in their later papers. Dr Williams wrapped up the rooftop solar observing in 1948 and soon returned to optical astronomy, working with the Perth Observatory and serving as president of the Astronomical Society of WA. The image above is an annotated chart record showing 75 MHz bursts and enhanced emission recorded in Perth on 25 September 1946, taken from a letter from S.E. Williams to Joe Pawsey and reproduced in the paper The genesis of solar radio astronomy in Australia by Orchiston, Slee and Burman. (Image credit: Radiophysics Archives) |