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Ohio-State Astronomy Professor Emeritus Arne Slettebak died May 20th 1999 following a recent illness. Arne was born of Norwegian parents in the Danzig Free State on August 8th 1925 and emigrated to the United States with his family in 1927. He became a United States citizen in 1932 and graduated with a B.S. in Physics from the University of Chicago in 1945 and a Ph.D. in 1949. He began his professional career as an Instructor at The Ohio-State University in 1949, advancing to Full Professor ten years later when he assumed the directorship of Perkins observatory: a position which he held until 1978. He was instrumental in returning astronomy at The Ohio State University to the status of a separated department which he chaired from 1962 until 1978. His tenure as chairman was focused on building the department with a well rounded staff and supervising its growth from the decaying old McMillin Observatory and Orton Hall to quarters in the then new addition to the Smith Physics Laboratory. He engineered an agreement between The Ohio-State University, Ohio Wesleyan University and the Lowell Observatory whereby the 69-inch telescope located at the Perkins Observatory in Delaware, Ohio was moved to the Lowell Observatory and the optics up-graded to a 72-inch cassegrain which served as the department's primary research instrument for more than three decades. Arne retired from The Ohio-State University in 1994 after 45 years of service, but continued to be active in his research interest until his death.
His research interests centered around Be stars and stellar rotation. Arne bridged the gap between the largely morphological astronomers of the first half of the century and the more quantitative efforts ushered in by computing advances in the second half of the century. His careful and detailed observations of stellar rotational velocities, interpreted initially with the graphical models of Shajn and Struve, were later re-interpreted with far more rigorous rotating model atmospheres and still constitute some of the most reliable projected rotational velocities in the literature. His years of poring over the shallow line profiles of the most rapidly rotating stars left him with a profound understanding of the systematic errors inherent in determining their projected velocities. It is these conservative error estimates that lend such authority to his results. He also developed a remarkable physical intuition into the processes that must be present in Be stars. I was fortunate to join the staff of the newly emerging astronomy department at The Ohio State University in the early 60's. While it would take me years to fully appreciate the deftness of his leadership in an environment often hostile to scholarly endeavors, it was clear from the outset that here was a kind and fair-minded man. One can do far worse for a leader. I believe it was this fairness that won him the respect of the wider astronomical community and which led to numerous positions in many venues. He was a Councilor for the American Astronomical Society from 1964 to 1967 and served on the Education and External Awards committee of that organization. He served as an active member of Commissions 29 and 45 of the International Astronomical Union and was Vice President and then President of Commission 45 on Stellar Classification from 1976 to 1982. He represented The Ohio-State University on the AURA board from 1961 to 1978 and was chairman of the AURA Scientific Committee from 1970 to 1973.
However, it was his love of Be stars that held his research interests from his Doctoral Thesis until his death. He organized IAU colloquia (No. 4 and No. 92 with Ted Snow) on the subject repeatedly during his career and was instrumental in other conferences on the subject. Ironically IAU Colloquium 175 on Be stars was to be dedicated to him, but with characteristic humility he asked that it be dedicated to Mercedes Jaschek. He and Carlos Jaschek were both to eulogize her, but with the recent passing of both of them, the task must be left to others. In this age of mass data acquisition, it would be easy to forget the understanding, hard-wrought from photographic spectra, scanned with microdensitometers, and hand-reduced from strip chart recordings. However, it was astronomers like Arne Slettebak matching every hour hand-guiding single channel spectrographs on modest telescopes with multiple hours of tedious data reduction who provided the basis for our present understanding of stellar astrophysics. The difficulties of obtaining good useful data were so large that many succumbed to the temptation to cut occasional corners. Arne never did and that is the reason his results are still held in such high esteem. Throughout my career trying to provide a theoretical understand of rotating stellar atmospheres, I never ceased to marvel at Arne's patience and thoroughness in probing the mysteries of rotating stars. While he must have been frustrated with the slow rate of progress in the subject, he never showed it. He was one of the most even-tempered men I have ever known and truly deserved the appellation of gentle man. Astronomy has lost a steadfast and determined observer and we have lost a truly decent and kind colleague.
George W. Collins, II
Photos are courtesy of Gerrie Peters. |
