The 2002 Symposium was organised by the Pretoria Centre and held at the Aloe Ridge Hotel in Muldersdrift from the 29 November to 1 December. A daily average of about 60 national and international delegates ensured a well attended and representative audience.
Tim Cooper, President of ASSA, opened the symposium and introduced the keynote speaker, Professor Brian Warner, from the University of Cape Town. Professor Warner delivered a paper titled "Stellar Apoplexy, Convalescence and Recovery", a rather daunting title to an extremely interesting topic covering eruptive novae and cataclysmic binary systems. His excellent explanation and demonstration techniques enabled the audience to easily assimilate the relationship between a white dwarf and a parent star in a binary system. Here, stellar matter is transferred from the parent star into an accretion disk around the white dwarf, eventually to accumulate onto its surface in ever-increasing quantities until an outburst or nuclear-type explosion is witnessed and recorded as an outburst.
Dr Janet Mattei, Director of the American Association of Variable Star Observers (AAVSO) followed Professor Warner with the Danie Overbeek Memorial Lecture. This lecture was sub-titled "Contributions of Amateur Astronomers to Variable Star Research". By the end of Dr Mattei’s lecture, the audience was in no doubt as to Danie’s gargantuan contribution to amateur astronomy through more than 287 000 recorded observations of variable star activity over 50 years. This equates to an average of more than 15 recordings every night for 50 years! Danie’s observations were of such significance and importance that they were routinely used by Hubble Space Telescope teams for pointing and calibration exercises. Dr Mattei demonstrated how, since Danie’s passing, there has been a significant gap left in the observations of many key variables and she appealed to the South African astronomical community to take up the practice of variable star observing.
Professor Fabio Frescura from the University of the Witwatersrand is a theoretical physicist. His dry, humorous style produced an entertaining and fascinating account of pulsars – those rapidly spinning, super-dense remnants of supernovae explosions. "The density of matter in these neutron stars is sometimes only exceeded by certain students in my classes."
The post-lunch sessions were characterised by short, high impact sessions. These included segments on the Boyden Observatory, the Lamont-Hussey Observatory and the Hartebeeshoek Radio Observatory. All speakers encouraged amateur astronomers to visit these observatories and learn about the research projects in progress. For example, HartRao is currently involved in a collaborative project to measure continental drift (specifically, the movement of the African continent) to millimetre-accuracy.
Professor Derck Smits of UNISA tantalised his audience with a fascinating variable-type: W Ursa Majoris. After tea, our own Brian Fraser presented a look into the formation of O2 in the early atmosphere.
The final presentation of the day was Berto Monard’s Supernova Search Program – long awaited by the amateur astronomy community. Berto has now made seven supernovae discoveries with his 12 inch Schmitt Cassegrain telescope and CCD camera in his home-built Bronberg Observatory, north of Pretoria. He spoke about his methodology as well as technical aspects behind the supernova search program. Berto’s dedication and tenacity for his search is inspiring to all.
Tim Cooper opened the Symposium’s second day with "Recent ASSA results on Comets and Meteors". He appealed to all amateurs to contribute observations to him as often as possible. Together with variable star observations, this is an area in which amateur astronomers can contribute to science in a tangible and useful manner.
Brian Fraser again took the lecturn and spoke to us about the strange and unpredictable variable, delta Scorpii. Here too, amateurs should contribute naked eye observations as often as possible to help in the understanding of this star’s behaviour.
Past ASSA-Jhb Chairman, Trevor Gould, presented a half-hour segment on the SA Meteorite Recovery Program, with the gist of his talk being the importance of changing current restrictive legislation regarding the discovery and ownership of meteoritic samples.
After tea, Pretoria Centre’s Michael Poll read a paper entitled "Variable Stars" on behalf of Jan Hers. Thereafter, Chris de Coning spoke about the new ASSA Historical Section website and appealed to everybody to inspect the site and inform him of any errors and omissions. The site address is:
http://www.saao.ac.za/assa/history.html .
Magda Streicher’s eagerly awaited "Deep Sky Dedication" was presented with poise and enthusiasm. Her meticulously crafted hand-drawings were juxtaposed with CCD image equivalents, which, in many instances, were quite inferior to her visual acuity and subtle detail she so carefully sketched. Rupert Hurly presented the Double Star Award to Magda for her dedication and service to the Double Star Section.
Theo Pistorius of the Imaging Section, spoke on the "Construction and Use of an Audine CCD Camera". The complete plans and schematics for this camera are available for free download via the internet. I didn’t agree with his "anyone can build one" maxim as I personally know I would be sorely lacking in the more-than-casual passing knowledge in mechanics and electronics necessary to build an electronic circuit board, cooling device, etc. However, his CCD images from his home-built camera presented a very satisfactory alternative to expensive commercially-available CCD cameras.
The afternoon sessions were devoted to the historical aspects of astronomy in South Africa. Neville Young read a paper on behalf of Peter Smits titled "Early History of Astronomy in South Africa", including a fascinating account of John Herschel’s work at the Cape. Tim Cooper spoke on "A history of Comet Discovery from South Africa" and he again encouraged amateur astronomers to participate in comet searching and observing. The last comet to be discovered from Southern Africa was in 1978 by José Campos; we need more comet hunters to improve this rather sparse record. Rupert Hurly spoke on "De la Caille at the Cape 1751 – 1753" and Louis Barendse completed the day’s presentations with "The Invention and Development of the Telescope" – a thought-provoking talk in which he subtly suggests that Leonardo da Vinci be credited with the invention of the astronomical telescope.
That evening, we were treated to a tour of the Aloe Ridge 16 inch Schmitt Cassegrain and the newly-acquired 25 inch Newtonian reflector. Cloudy skies (again!) precluded us from sampling the views from these magnificent instruments.
I was unfortunately unable to attend the final third day of the symposium. I personally benefited tremendously from my 2-day experience and came away highly motivated and charged. The symposium has taken my love for astronomy to a new level and I’m charged with new ideas and observing projects that will keep me very busy until the next symposium in 2004. The organisation and event management was impeccable to the credit of the Pretoria Centre. Was the price charged for the event reasonable? Yes! Was it worth it? More than worth it. The personal growth and advancement from an event of this nature will be felt for many years to come.
The presence at the Symposium of Executive Editor of Sky and Telescope, J Kelly Beatty, made me think that many more of our local enthusiasts should have attended this event. Book your seat early for 2004 and don’t miss it again!
Dave Gordon