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After accepting a beginning position at the University of Illinois Department of Astronomy in 1964, I was told I would be joined by Ken Yoss, who had been hired as full professor. By odd coincidence, I had worked for him as a beginning grad student teaching assistant in 1960 at the University of Michigan, where Ken was taking a summer break from Mt. Holyoke as visiting professor. When I arrived in Urbana on a long trip from the west coast en route to pick up my family on the east coast, he and his wife Norma Lee graciously hosted me at their new home, where Ken offered storage space to relieve my packed car. Such were my introductions to a warm, giving man who could not do enough for his family, friends, and colleagues. And he kept giving friendship through his retirement from the U of I in 1992 until, after a brief illness, he passed away on August 4, 2012, in Fort Wayne, Indiana, where he had moved after his marriage in 2002 to Pearl Harber.
Ken was born on January 13, 1926, in Hudson, Iowa, to Fred and Charlotte Yoss. His brother Robert and sister Jeannette Gibson preceded him in death. He began his professional life at the University of Michigan in 1943. After his first college year he proudly served in the US Army (medical corps) from 1944 until 1946, the latter part in postwar Japan. Returning to school, he received his Bachelor's degree in 1948, and then his doctorate in 1953. He started his long teaching and research career at Wilson College, then moved on to a long stint (from 1953 to 1959) at Louisiana State University, where he met and, in 1955, married Norma Lee Henkel. Following his service at Mt. Holyoke between 1959 and 1964, he settled in at Illinois, where he taught introductory astronomy and his advanced specialty, the dynamics and structure of the Galaxy. In between, in 1962 and 1963 he had held a position as visiting lecturer at Harvard's Summer Institute for Observers at the Agassis Station. Ken was especially adept at working with and guiding graduate students who went on to distinguished careers of their own.
A dedicated astronomer, Ken loved observing, and specialized in studies of the galactic poles. He was happiest examining the spectra, velocities, and abundances of metal-poor and high velocity stars, particularly those of late-type giants, and was well known for his work on kinematic and abundance gradients in the Galaxy. Among his early works were measures of photored magnitudes of the North Polar Sequence, comet spectra, and studies of objective prism spectra that led to his later career doing spectroscopy and photometry of the stars of the galactic halo, as well as those of clusters. By the time of his death he had written or contributed to more than 80 publications. Given any chance, he'd proudly show off his vast collection of low resolution spectra of K giants and other stars of polar interest. And he never stopped, coming to the office on a regular basis after retirement, and even (when he could make the long drive) after his move to Fort Wayne in 2006.
Among his greatest contributions was his leadership in developing the 40-inch telescope at the Prairie Observatory under the dark skies south of Champaign-Urbana. After much searching for sites, he even found a "mountain" some 10 or so feet high (this being Illinois) on which to place it. Completed around 1969, the telescope was remarkably effective both in Illinois and after its move to San Diego State's Mt. Laguna Observatory in 1981. It continues to serve yet today as a powerful photometric and spectroscopic tool. Ken always at the forefront, the telescope was among the first to be equipped with an automatic digital drive that could accurately and quickly place it onto an astronomical object.
Above all, Ken was dedicated to family and friends. With Norma Lee, who passed away in 2001, he had three daughters, Roberta Hursthouse, Barbara and Ann Yoss, and one grandson, Scott. After marriage to Pearl, his loving step family included three more sons, two more daughters, and 11 more grandchildren. Ken's local obituary told of "a very loving man who never met a stranger," one who I knew personally almost always had a smile on his face. He loved playing cards and board games as well as the simple pleasure of walking. A calming and unifying force within the Department, he organized fun and friendly Friday lunches at the now-gone Embassy in Urbana.
In addition to being a member of the AAS and the Covenant United Methodist Church, he (not surprisingly) also belonged to the Fort Wayne Astronomical Society and had been a long-time member of the Astronomical Society of the Pacific. Ken and his sunny demeanor, as well as his excitement over the stars of the galactic halo and poles, will be greatly missed by those who crossed his path.
Obituary written by: Jim Kaler (Department of Astronomy, University of Illinois)
BAAS Citation: BAAS, 2012, 44, 016