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21st of August 2015
ATNF Colloquium
Found: The Original 1945 Records of Australian Radio Astronomy - Collaroy Observations
by Miller Goss (NRAO)
In July 2014, Miller Goss, Ron Ekers and Helen Sim found the original records of the first published Australian radio astronomy observations. These were obtained by Joseph L. Pawsey and Ruby Payne-Scott in early October 1945. The observations gave strong evidence of a hot million degree corona as well as frequent radio bursts. These observations formed the basis for a number of pioneering publications: the 9 Feb 1946 Nature paper of Pawsey, Payne-Scott and McCready, the major publication of the initial Australian radio solar publications of McCready, Pawsey and Payne-Scott in the Proceedings of the Royal Society of London in Aug 1947 and Pawsey's presentation of the radio properties of the million degree corona in Nature on 2 Nov 1946 (shown above).

Contemporaneously with these publications, D.F. Martyn, Ginzburg and Shklovsky were all involved in independent theoretical studies of the properties of the solar corona. The back-to-back Martyn and Pawsey Nature papers were the first that described the radio properties of the hot corona, caused by free-free emission in the corona. The contents of this exciting discovery provides important clues to the thought processes of Pawsey and Payne-Scott as they attempted to decipher the complex, time variable radio emission of the sun at 200 MHz or a wavelength of 1.5 metre during the first few months of Australian radio astronomy observations. The division of the observed emission into "bursting" and "quiet" modes was challenging for the novice radio astronomers.

These records had been recognized by Paul Wild in 1968, who instructed the CSIRO Division of Radiophysics secretary to E.("Taffy") G. Bowen- Ms. Sally Atkinson, to submit these to the Australian Academy of Science. Wild characterized these documents as "of considerable historical interest". Apparently the transmission of the documents was not done; a thorough search of the Australian Academy Library in August 2014 failed to locate them. The original papers were only found in Ms. Atkinson's files after her death on 13 November 2012 in Sydney. We have also found images of the RAAF antenna (LW/AW RP radar aerial) in the collection of the Warringah Council. Hastings Pawsey and Goss will visit the site on Collaroy Plateau on 14 August after visiting the Council personnel in the Local Studies and Family History Section of the Warringah Council Library. One of the images includes a small S band aerial used for telemetry, likely a project on which Ron Bracewell worked in 1943.

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