~ . ,.r; . ~ • 58/1964 •4.: • THE AUSTRALIAN NATIONAL UNIVERSITY RESEARCH SCHOOL OF PHYSICAL SCIENCES DEPARTMENT OF ASTRONOMY ANNUAL REPORT 1963 Staff Professor of Astronomy and B.J. Bok, Ph.D. Director of Observatory Professor of Optics T. Dunham, Ph.D. Reader and Deputy Director A.R. Hogg, D.Sc., F. Inst. P., (Administration) F.A.A. Reader and Assistant Director S.C.B. Gascoigne, M.Sc., Ph.D. (Research) Reader B.E. Westerlund, Ph.D. Head of Section on Positional H.J.McK. Abraham, M.Sc. Astronomy (Senior Fellow) Senior Fellows w. Buscombe, M.A., Ph.D. Th. Walraven, Ph.D. Fellows H. R. F. Go 11 now, Dr. Phi 1. A. Przybylski, Ph.D. A.W. Rodgers, Ph.D. L. Searle, Ph.D. Research Engineers (Fellows) K. Gottlieb, Dip. Ing. L.C. Witchard, B.Sc. Visiting Fellow Madge G. Adam, D. Phil. Research Assistants J.M. Basinski P. Morris Kennedy Honorary Professor R.V.d.R. Woolley, Kt., O.B.E., M.Sc., F.A.Ao, F.R.S., Astronomer Royal Honorary Fellow c. Roslund, Ph.D. Research Scholars R. Bhavilai, M.Sc. R.D. Ekers, B.Sc. J. Koehler, B.Sc. D.K. Milne, B.sc. R.M. Price, B.Sc. LoF. Smith, B.Sc. N. Visvanathan, B.Sc. B.L. Webster, B.Sc. Three major appointments were made during the year: that of Dr. Walraven to the post of Senior Fellow, Dr. Searle to the post of Fellow and Mr. Witchard to the post of Research Engineer. At the end of the year our Workshop Foreman, Mr. H.J. Banham, retired after nearly forty years service to the Observatory. Another resignation was that of Mrs. C.M. Wehner, after sixteen years in which she did much good work in the Time Service and Section on Positional Astronomy and on the Computer Committee. 58/1964 - 2 - The year 1963 marked the end of eleven years of association between the Yale and Columbia Observatories and Mount Stromlo Observatory. In July the Yale-Columbia Observer, Mr. c. Jackson, left Canberra to return to South Africa and the Yale-Columbia 26-inch Refractor, an instrument that received great renown as the producer of most southern trigonometric parallaxes, was transferred as a gift to the Australian National University. The Uppsala Observer, Dr. G. LyngS, left in July and was replaced by Dr. c. Roslund. The close association between the Uppsala Station and Mount Stromlo Observatory continues. Visitors Dr. B.E. Pagel of the Royal Greenwich Observatory spent eight months at the Observatory on an exchange arrangement whereby Dr. Gascoigne was able to spend eight months at Hestmonceux Castle. Both Dr. Pagel and Dr. Gascoigne derived much benefit from their exchange. Dr. P.W. Hodge from the University of California was with us for three months; Dr. Madge G. Adam from Oxford University arrived in September and will remain at the Observatory for the first half of 1964. During the year we had visits from many distinguished astronomers from Australia and overseas. The IAU/URSI Symposium No. 20 on "The Galaxy and the Magellanic Clouds", which was held in Canberra and Sydney during March, brought to Australia more than twenty distinguished astronomers from overseas including the President of the Union, Professor V.A. Ambartsumian of the USSR, two Vice-Presidents, Dr. G. Haro of Mexico (who also gave a colloquium) and Dr. R.H. Stoy of the Royal Observatory of the Cape of Good Hope, and two Past Presidents, Professor J.H. Oort of the Netherlands and Professor B. Lindblad of Sweden, all of whom visited the Observatory. In addition we had the following visitors who gave colloquia:- Dr. R.A. Lyttleton of the University of Cambridge, Dr. W. Krzeminski of Warsaw Observatory, Dr. J.F. Heard of Toronto University, Professor L. Perek of Czechoslovakia, Professor A. Blaauw of Groningen, Dr. H.L. Johnson of the University of Arizona, Dr. G. Herzberg of Ottawa, Dr. J.W. Warwick of Boulder, Colorado, Dr. R.D. Davies of the Jodrell Bank Radio Observatory, Dr. M. Morimoto of Japan, Professor M.G.J. Minnaert of Utrecht and Dr. E.M. Purcell of Harvard University. Additional overseas visitors were Professor H. Bondi of the University of London and Dr. G.Z. Dimitroff of Dartmouth College, U.S.A. Among colloquia speakers from Australia we note Dr. Grote Reber and Professor G.R.H. Ellis from Tasmania and Dr. J. Ramsay from the National Standards Laboratory of the c.s.I.R.O. In August Dr. D. Mugglestone of the University of Queensland spent two weeks hereo Dr. F.J. Kerr of the Radiophysics Laboratory of the C.S.I.R.O. gave a series of seminars during April and May. Dr. R.A. Bell from the University of Adelaide spent the period from March to August at the Observatory and participated in the Seminar Programme for the second term. Student Activities Five Doctoral Theses were completed during 1963. These were:- D.J. Faulkner 11 A study of the 30 Doradus and 7t, Carinae Nebulae"; R.R. Shobbrook "Photographic, specto­ graphic and photometric studies of southern galaxies"; I.J. Danziger "A high dispersion spectral study of one carbon and two barium stars"; D. Sher "Distances of some open clusters near '>t Carinae"; J.A. Graham 11 The application of hydrogen-line photometry to Milky Way research". 58/1964 - 3 - The Joint Programme with the C.S.l.R.O. is operating satisfactorily. Mr. Price and Mr. Koehler are working in the field of radio astronomy at Parkes and at Sydney (Radiophysics Laboratory); Mr. Bhavilai is about to complete his thesis on solar astronomy in Sydney (Division of Physics); Mr. Ekers will start work on his thesis in Sydney (Radiophysics Laboratory) about the middle of 1964. The Summer Vacation Scholar scheme is again in operation this year with eight scholars attending. Field Station and Site Testing At Siding Spring Observatory, the buildings are ready to receive the 40-inch and 16·4 inch Reflectors when these arrive in January 1964. The two telescopes have been constructed by the firm of Boller and Chivens of Pasadena, California, and they have optics by the Perkins-Elmer Corporation of Casta Mesa, California. The 40-inch Reflector has Ritchey-Chretien optics and should have a usable field for photography of one square degree at f /8. The testing of the optics to the required tolerance has been kindly supervised by Dr. l.S. Bowen, Director of Mount Wilson and Palomar Observatories. Dr. Gascoigne, assisted by Mr. Wehner, will be in charge of mounting and adjusting the telescop~s prior to operation. Two additional telescopes are scheduled for mounting at Siding Spring Observatory in the rext few years. The 26-inch Reflector from Mount Bingar has been dismantled, and the mirror, which was on loan from the Fund for Astrophysical Research, has been returned. New Cassegrain optics will be ordered for this instrument, which will be erected at Siding Spring. The 50-inch Reflector from Mount Stromlo Observatory will also be transferred to Siding Spring as soon as practicable. Work on the buildings for these two telescopes is in the advanced planning stage. Records of the night sky at Coonabarabran are given below. The observations consist of noting cloud or haze at 9 p.m.; "zero cloud" being defined as no cloud or haze more than 10° above the horizon. Clear or cloudy skies the following morning are also noted - indicative of stability overnight. The mean percentage of "zero Cloud" at Coonabarabran is 58.5% and the mean of clear skies the following morning is 48.1%. It is of interest to compare these figures with those for Mount Stromlo, where the two means for 1963 were respectively 25.4% of "zero cloud" at 9 p.m. and 1410 of clear skies after "zero cloud'' at 9 p.m. The total obs~rving hours at Mount Stromlo Observatory during 1963 were photoelectric 785.5 hours, spectrographic 1413 hours. Dr. Hogg has continued the Site Testing Surveys on an Australia-wide basis; results have been disappointing. However, records show that 1963 was an unusually poor year. The principal activity was the maintenance of an observing station on Mount Singleton in Western Australia from November to March inclusive. Observations of the Danjon seeing index, photoelectric extinction measures, wind velocity, cloud data, air and ground temperature records and estimates of duration of clear sky were obtained. The whole project has been hampered by unusually high rainfall, which not only prevented observations, but created difficulties with the access track to the mountain. Further, the volcanic eruption in Bali has undoubtedly resulted in much larger amounts of dust than usual being present at high levels in the atmosphere. 58/1964 - 4 - Estimates of the amount of clear sky occurring in runs of at least four consecutive hours have been made at Mount Stromlo by visual observation and at Mount Singleton by examination of net radiometer recordso The results are: Percentage of nights on which runs of at least four hours took place: Mount Stromlo 23% Mount Singleton 32% Expressed as the percentage of the possible observing hours covered by the four hour or longer runs, the results are: Mount Stromlo 17% Mount Singleton 25% Another comparison can be based on the percentage frequency of occurrence of "zero cloud". Here the figures are: Mount Stromlo 23% Mount Singleton 24% The results from Mount Singleton are extremely dis­ appointing, representing probably no more than 1000 hours of photoelectric time per year, though probably this would have been increased had the summer months been included. It is also difficult to assess just how far the test period represents abnormal conditions.