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Alexander W. Rodgers (1932 - 1997)

Alexander Rodgers died on Friday the 10th of October 1997.

Alexander W. (Alex) Rodgers, internationally known astrophysicist and professor of astronomy at the Australian National University (ANU) died on October 10, 1997, just weeks short of his scheduled retirement. He is survived by his wife, Ruth, and three children.

Alex was born in Newcastle, New South Wales, on May 24, 1932, and grew up close to the BHP Steelworks where his father worked. He studied science at Armidale, a College of the University of Sydney, graduating with honors in 1953 and receiving the H. N. Russell Prize in astronomy. Rodgers started his career at Mt. Stromlo as a student with Richard Wooley (later Astronomer Royal). He graduated in 1958 and, after a year as a postdoc at the Carnegie Observatories in Pasadena and a stay of some months at the Royal Greenwich Observatory (with a Fulbright Fellowship 1958-59), he returned to Stromlo, where he remained for the rest of his career. He was director from 1986 to 1992 and the Pawsey Memorial Lecturer at the Australian Institute of Physics in 1985. He was a member of the Australian National Committee of Astronomy and chaired or served on several of its working groups and on the AAO time assignment committee.

Of Rodgers' contributions to Stromlo, the most important was his role during the 1960s in bringing about the transformation of the Observatory from an old tradition of descriptive and positional astronomy to a new tradition of modem astrophysics. With Searle and Gascoigne, Alex supervised almost all of the Mt. Stromlo Observatory (MSO) graduate students during the 1960s. As one of the original group of new students, Roger Bell remembers how helpful and influential Alex was and how he learned more from Alex than from his formal supervisors. Alex's eagerness and keen interest in astronomy were infectious and made for a very stimulating atmosphere. His later graduate students included Barry Newell, Mike Bessell, Ed Schmidt, W. J. Couch, Elaine Sadler, Luc Binette, Peter Quinn, Kavan Ratnatunga, S. J. Meatheringham, B. F. Roukema, and many others less well known outside Australia.

Alex had a great interest in instrumentation and was responsible for that aspect of Stromlo for most of his career. In the beginning, his experience in Pasadena and his friendship with J. B. Oke were a great help to him. His first instrument was a single-channel spectrophotometer for the old 50-inch telescope in the 1960s.

The 74-inch telescope was his favorite and the major spectroscopic tool in Australia until the advent of the Anglo-Australian 3.9 meter and the 2.3 meter. Alex led the transformation from the painful era of photographic spectroscopy in the 1960s into the semi-electronic age of the image tube and on into the present epoch of fully electronic detectors. He chose the photon counting route and built the systems which were the staple detectors from 1978 until CCDs took over in about 1990. For the new Siding Spring 2.3 meter, he built both a double-beam spectrometer and an imager still in use.

Much of Rodgers' early research used a coudé spectrograph constructed at Stromlo under the leadership of Theodore Dunham. He applied what was then the only high dispersion spectrograph in the southern hemisphere to studies of Cepheid variables, measurement of radial velocities, stellar abundances, temperature variations, and hydrogen line profiles.

Alex is probably most famous for his work on the metal-rich main sequence A stars that lie in the halo, far above the galactic plane. He argued that these were the result of smaller galaxies falling into ours. This idea is now commonplace, but published with Harding and Sadler in 1991, it was way ahead of its time.

Among his other stellar research were (a) study of blue horizontal branch stars in globular clusters with Searle and Newell, (b) demonstration of the range of metal abundances for stars in Omega Centauri with Ken Freeman, and (c) recognition of the retrograde orbits of second-parameter globular clusters, in collaboration with Paltoglou, as evidence of their origins in an accretion event.

Alex's instrumental contributions culminated in the transformation of the decrepit Great Melbourne Telescope (from 1868) into an outstanding computer-controlled, wide field, imaging telescope for the MACHO dark matter search. The MACHO project has also discovered large numbers of RR Lyrae stars, and after Rodgers stepped down as MSO director, he began a series of papers on these stars and was working on them until his last few days.

In addition to the American Astronomical Society, Rodgers was a member of the International Astronomical Union (Commissions 27, 29, and 46) and of the Astronomical Society of India. Alex was a quirky character with a larrikin streak and an affinity for the rebellious elements of society. But he always wore a jacket and tie when observing. Many of his colleagues have commented on his unusual wit and sense of humor: We refer the reader to an offbeat joke that he managed to work into a paper in PASP (1973, v. 85, p. 270, col. 2, lines 27-28).

We remember with gratitude Alex's achievements, his contributions to Mount Stromlo and Siding Spring Observatories, and his guidance and friendship. His scientific papers are currently stored at MSO, but it is hoped that they will eventually be archived at the Australian National University.

Photo (available in the PDF version) from The Australia National University Reporter.

Affiliations: 

Australian National University

Obituary Written By: 
Ken Freeman (Mount Stromlo Observatory), Fiona Aplin (Mount Stromlo Observatory), Roger Bell (University of Maryland)
BAAS: BAAS, 1998, 30, 1464
DOI: 
10.3847/BAASOBIT1998012