In 1935 he married Muriel E. Mussells; they had a son, Carl Keenan, Jr., and a daughter, Gail Carol.
In 1936, he joined the Yerkes Observatory staff formed for establishing the new McDonald Observatory. He served as a staff member at McDonald from 1936 to 1940, where he collaborated with Daniel M. Popper on properties of faint B stars, and continued his investigations on colors in spiral galaxies.
From 1940 to 1942 he was at Mt. Wilson Observatory as a National Research Council Fellow; here he studied a class of active galaxies, now called Seyfert galaxies. In 1942, he returned to Cleveland and went to the Case Institute to teach navigation to armed forces, and to participate in secret military research. Despite wartime, he managed to carry out some astronomical research at the Warner and Swasey Observatory of the Case Institute, equipped with a new Schmidt telescope and objective prism, together with J.J. Nassau and S.W. McCuskey.
In 1946, Seyfert joined the faculty of Vanderbilt University in Nashville, Tennessee. At that time, the university only had the small Barnard Observatory, equipped with a 6-inch refractor, which had once been used by Barnard, and only a modest teaching program in astronomy. With considerable vigor, Seyfert starting a new series of courses, and took effort to build a new observatory. Within a few years, while busy wirh full-time duties in teaching and research, Seyfert managed to get public support from the Nashville community. During the work-intensivee planning and construction of the new observatory, he still found time to give astronomy lectures outside the university, and even appeared in television as daily weather-forecaster. The new Arthur J. Dyer Observatory, equipped with a 24-inch reflector telescope, was finally completed in December 1953. Carl Seyfert became director of Dyer Observatory, a post he held for the rest of his life. Research at the new observatory included stellar and galactic astronomy, as well as new instrumental techniques.
Seyfert was a member in several professional societies, including the American Astronomical Society, where he served on the Council from 1955 to 1958, and the British Royal Astronomical Society. He also served in the Associated Universities Incorporated, as a member of the Board of Directors of the Association of Universities for Research in Astronomy (AURA), and in the Astronomy Advisory Panel of the National Science Foundation (NSF).
Carl Seyfert died on June 13, 1960 in Nashville; Tennessee, in an automobile accident, aged 49.
He was honored by the astronomical community by the naming of Moon crater Seyfert (29.1N, 114.6E, 110 km diam) in 1970. The 24-inch telescope at Dyer Observatory for which he had worked so much now carries his name, "Seyfert Telescope." His name is remembered by astronomers by the name of the "Seyfert Sextet" for a group of galaxies he has studied, and most widely by the designation "Seyfert Galaxies" or "Seyfert AGNs" for a class of active galaxies he discovered.
Seyfert's contributions to Astronomy
Carl Seyfert contributed to many fields of astronomy, documented by the large number of published papers. His research covered stellar and galactic astronomy, frequently spectroscopic studies, as well as observing methods and instrumentation.
During his time in Harvard, notably investigations of the colors, magnitudes and color indices of galaxies resulted. At McDonald, he investigated the properties, in particular spectroscopic, of B stars and large PM stars, and did some work on variables. Also, he studied the distribution of colors, emission nebulae and clusters in galaxies.
At Mt. Wilson, he did pioneering research of nuclear emission in spiral galaxies: In 1943, he published a paper on galaxies with bright nuclei that emit light with emission line spectrum, and exhibit characteristically broadened emission lines. These galaxies are since called Seyfert Galaxies; the most prominent example, identified as such by Seyfert, is Messier 77 (NGC 1068). Since, the class of Seyfert galaxies has been shown to be a subclass of a much wider group, the galaxies with Active Galactic Nuclei (AGNs).
At Warner Swasey Observatory and the Case Institute, his astronomical research included stars and nebulae in the Andromeda Galaxy M31, spectral luminosity distribution of planetary nebulae, stellar spectra and lumionosity function of stars in the Milky Way. At that time, together with Nassau, he also obtained the first good color photographs of nebulae and stellar spectra.
During the time at Vanderbilt, research included first the photometric investigation of photographic plates of Barnard Observatory, and Shapley's Harvard plates. In 1951, he observed and described a group of galaxies around NGC 6027, now known as "Seyfert's Sextet." He was involved in instrumental innovations including the use of photomultiplier tubes and television techniques in astronomy, and electronically controled telescope drives. Scientific results were obtained on variable stars, emission B stars in stellar associations, and the Milky Way structure.