John R. Stauffer died on Friday the 29th of January, 2021.
John R. Stauffer was a leading stellar astronomer of his era. One of the pioneers of the study of the angular momentum, chromospheric activity, and evolution of young stars, John was also a leader in many space missions as an integral part of his multifaceted career.
John was born in Findlay, Ohio, in 1952 to Ken and Nana Stauffer. He was valedictorian of his graduating class from Findlay High School in 1970 and then attended Case Western Reserve University in Cleveland, Ohio, where he received his B.S. in 1974, followed by his Ph.D. in Astronomy from the University of California at Berkeley in 1981.
John began his career in astronomy with a postdoctoral fellowship at the Harvard-Smithsonian Center for Astrophysics (CfA) through 1984, followed by a National Research Council Postdoctoral fellowship at the Dominion Astrophysical Observatory in Victoria, British Columbia, through 1986. After a stint at NASA Ames Research Center as a SIRTF postdoc (the pre-launch name of the Spitzer Space Telescope), John served as the Project Scientist and head of the Science Center at CfA for the Submillimeter Wave Astronomy Satellite from 1991 to 2000. He was an integral member of the IRAC Guaranteed Time Observations team for Spitzer. John concluded his professional career at the Infrared Processing and Analysis Center (IPAC) at Caltech, Pasadena, California, where he was the System Scientist for the Spitzer Science Center from 2000 until his retirement in 2018. From 2004 to 2008 he was also head of the science staff at IPAC. John contributed critical improvements to Spitzer science operations, including leading the effort to improve Spitzer’s pointing, which improved the photometric stability of exoplanet observations.
Although John's thesis topic dealt with the nuclei of disk galaxies, his first love was studying the properties of the Pleiades star cluster, which led to a long career studying the angular momenta and activity of young low-mass stars, and the relation to other properties. His seminal work on the remarkable distribution of rotation among Pleiades stars — a combination of very fast and very slow rotators — led to a completely new generation of models for stellar angular momentum evolution incorporating both winds and pre-main sequence magnetospheric coupling with circumstellar accretion disks, a field which is still not fully understood. He also made very significant contributions to other properties of low mass stars, especially in connection with their evolution, by studying several young stellar associations such as α Persei, the Hyades, Taurus, IC 2391/2602, and NGC 2264, to name a few.
In his later research, John led very ambitious programs which exploited the ability of the Kepler (and CoRoT) spacecraft to deliver remarkably precise photometry over extended blocks of time, enabling studies of the variability of pre-main sequence stars, especially in stellar associations of different ages. These observations, unbroken by day/night cycles and weather, revealed a previously undetected zoo of photometric changes, due to a combination of starspots, variable accretion, and time-dependent occultations by structures in dusty disks. In particular, the variations due to extinction by disk dust provided clues to the inner structure of protoplanetary disks, with many features that have yet to be explained satisfactorily. Here again John pioneered new avenues to gain a deeper knowledge in the early evolution of low-mass stars and the different phenomena connected to it.
John was a prolific scientist, writing nearly 350 refereed papers and a total of over 800 publications. He was also very active in the astronomical community by serving on different committees and advisory boards, including extensive involvement with the Cool Stars series of workshops. One of the remarkable aspects of John’s career was the sheer number of collaborators he had spanning many years and differing projects; for example, 50 of his collaborators were coauthors on 30 papers or more. This is the main reason why John had such a major impact on the careers of so many researchers and had so many scientific friends.
John was preceded in death by his first wife, Stepha Genelza. John and Stepha were married for 33 years. After retirement, John relocated to Pacific Grove, California to fulfill his dream of living by the ocean. In 2019 John married Linda Nunley. Despite his encroaching illness, John and Linda traveled extensively in the 22 months prior to his death due to pancreatic cancer. In addition to Linda, John is survived by his older brother, Bill and his nieces Laura, Sarah and Alissa; his nephew, Will; and two grand-nephews, Oliver and Owen. John was also stepfather to Jessica, Joshua and Josiah as well as a dear uncle to Novella Genelza.