Our colleague and collaborator George Hamilton Bowen, Jr., passed away November 1, 2009 in Ames, Iowa. George was born June 20, 1925 in Tulsa, Oklahoma to George and Dorothy (Huntington) Bowen. He married Marjorie Brown June 19, 1948 in Redondo Beach, California; they had five children, with eight grandchildren and five great-grandchildren at the time of his death.
George H. Bowen’s third or perhaps his fourth career was in astronomy. He was drafted into the navy in 1944, at the end of his first year as a student at Caltech, and ended his war-time service as an electronic technician on the aircraft carrier Shangri-La. He later said “In just nine months, starting from scratch (Ohm’s law!), we learned an amazing amount – not by memorization, of course, but by study and real understanding of the basic function of the most advanced AC circuits then being used for instrumentation, measurements, communications, control systems, and much more.” He gained a confidence that he could quickly and accurately diagnose and solve technical problems that stood him well in future work. One accomplishment he took particular pride in was figuring out how the radar control used cams and gears to solve the trigonometry for accurate pointing. He also described how the captain was alarmed when weather conditions changed so that refraction no longer showed them distant, small boats around the curvature of Earth.
After the war, George Bowen returned to undergraduate and eventually graduate study at Caltech, where he was recruited to the biophysics research group headed by future Nobel Laureate Max Delbrück. George often described his joy in working with these first-rate scientists and finding himself accepted as a part of the effort. He finished his BS with honors in 1949 and his PhD in 1953 with a thesis on “Kinetic Studies on the Mechanism of Photoreactivation of Bacteriophase T2 Inactivated by Ultraviolet Light” involving work with E Coli. This work was supported by grants from the U. S. Atomic Energy Commission and the National Foundation for Infantile Paralysis. George began a postdoctoral appointment in 1952 at Oak Ridge National Laboratory, still in biophysics, before being recruited to the Department of Physics at Iowa State in 1954. While he became Emeritus Professor in 1993, he continued with his research until health considerations took primacy around 2007.
When the biophysics effort in the Department of Physics split to form its own department in the early 1960s, George Bowen chose to stay with physics, commenting later that “It was clear to me that the important work was going to be in biochemistry and that was not my interest.” At that time he and his wife, recovering from polio, were parenting a large family, and this may also have influenced his choice. He spent the next decade focusing on improving the teaching of physics at Iowa State, revising and documenting the lecture demonstrations, teaching a generation of physics and engineering majors (including some later very successful scientists), and giving himself time for family and hobbies, notably color photography with a laboratory at home.
In the 1970s, George Bowen was ready to return to research, and found himself interested in the work being done in the astronomy program. Astronomy was a relatively recent addition to the department with just a few members. The newest arrival, Lee Anne Willson, was collaborating with Stephen Hill, an assistant professor at Michigan State and, coincidentally, one of the students who had benefited from Bowen’s physics courses at Iowa State. Bowen became intrigued by the physical problem of the relation of pulsation and mass loss in pulsating red giants. When Hill left astronomy to become a geophysicist with the oil company Conoco, George Bowen volunteered to take over the code he had written. Bowen quickly mastered the science and the technical skills needed for this project. A number of factors probably made this possible: In addition to his native intelligence and insight, he was building on experience with complex systems in biology, a clarity derived from his teaching experience, and his problem-solving introduction in the Navy. After six months of working with Hill’s code, Bowen started over and constructed his own code.
What distinguished the Bowen code from other programs that have been written to similar purpose was his consistent use of simple but reasonable approximations to allow study of the complex interactions among physical processes that contribute to mass-loss. This made a nimble code well suited to determining the essential physics of the process that takes most stars from red giants to white dwarfs, and keeps stars in the range of 1.4-4 solar masses from exploding as supernovae. Although Bowen did not publish many papers in his relatively short astronomy career, his 1988 “Dynamical modeling of long- period variable star atmospheres” describing the physics is still a much-cited classic, and his 1991 paper with Willson, “From wind to superwind - The evolution of mass-loss rates for Mira models”, laid out the essential properties of this important evolutionary stage.
George Bowen contributed to astronomy also as the main organizer for the 1986 American Astronomical Society meeting in Ames, IA. He was always ready to help a student or a colleague, taking a lot of time over a referee report or response to a letter of inquiry. Those of us privileged to work closely with him feel his continued influence in our approach to problems and our interactions with our students. Devoted to his family, a man of high intellectual integrity and talent, George H. Bowen’s legacy remains at Iowa State University and in the field of stellar astronomy.