Probst was deeply involved in the development of infrared instruments and two-dimensional array detectors for the U.S. national observatories.
Ronald George Probst passed away on Monday December 5, 2022 at his home in Tucson, Arizona, ending a six-year battle with cancer. He was 74.
Ron was born to Ernest and Mary (Gegner) Probst on November 23, 1948 in Crawfordsville, Indiana. He grew up in Plymouth, Indiana and graduated from Plymouth High School. While attending Indiana University, he met Judith Miller in the Astrophysics program, whom he married in 1972.
Ron graduated from Indiana University in 1971 with a B.A. with Distinction in Astrophysics and was elected to Pi Beta Kappa. He earned his Ph.D. from the University of Virginia in 1981. His thesis, “Infrared Detection of Very Low Mass Stars,” was directed by Dr. Robert O’Connell. Most of the data for Ron's Ph.D. thesis were obtained with the infrared (IR) photometers on telescopes at Kitt Peak National Observatory (KPNO) and Cerro Tololo Interamerican Observatory (CTIO).
After completing his thesis, Ron was a postdoctoral researcher at NASA Ames Research Center, where he continued his infrared work on very low-mass stars as a visiting observer at CTIO and KPNO.
In 1983, Ron moved to Tucson, Arizona to take a Scientist position at KPNO, which soon became a part of the National Optical Astronomy Observatory (NOAO). He was deeply involved in many NOAO developments in infrared instruments and detectors at a time when two-dimensional infrared arrays were just arriving on the astronomical scene. Most recently, he was the Principal Investigator on two heavily used infrared imagers, ISPI on the Victor M. Blanco 4‑m telescope in Chile, and NEWFIRM on the Mayall 4-m telescope at KPNO. NEWFIRM was so popular that it is the only instrument to have been moved from the Mayall to the Blanco, back to the Mayall, then (after the DESI installation) back to the Blanco to satisfy user demand. On January 11, 2023 NEWFIRM achieved “first light for the second time” on the Blanco. The Infrared Side Port Imager (ISPI) is a facility infrared camera at the CTIO Blanco 4-m telescope, serving a broad range of science programs. ISPI is getting a second life of its own, as it is being upgraded and moved to the Southern Astrophysical Research (SOAR) telescope - so that when that work is completed, both 4-m telescopes will be equipped with infrared imagers for which Ron was originally responsible.
One of Ron’s significant but often unrecognized contributions to NOAO was promoting, implementing, and supporting significant collaborative efforts between CTIO and KPNO. Many staff members (not just scientists) owe Ron a debt of gratitude for drawing them into rewarding and productive collaborations with their colleagues from the other hemisphere.
Ron’s Dark Energy Spectroscopic Instrument (DESI) collaborators recall his many contributions to the development phase of DESI before he retired at the end of 2017. Ron was the first author of the Operational Concepts Definition Document (DESI-0778), one of the foundational documents outlining how the proposed operational practices supported and were derived from the overall scientific goals. Ron was the chief telescope liaison for the ProtoDESI instrument, an important proof of concept for positioning fibers on celestial targets. He wrote the basic strategy document for the multi-step process of aligning the DESI Prime Focus Corrector to the primary mirror.
Ron was also our local expert on weather statistics and seeing improvements. It was his advocacy that resulted in the choice of the low-emissivity silver-gray paint now covering the Mayall dome at KPNO.
His work took him on trips to the observatories in Chile, ultimately bringing his wife and children on an extended sabbatical from 1995 - 1999. He used this time to travel the length and breadth - mostly length - of the country. He also picked up Spanish, but always joked that he spoke like a Chileno fishmonger. He was well known for his irreverent sense of humor.
Ron was committed to science education. He helped design an astronomy course for school children in Chile and performed public events (or supported them) while there. A memorable event was the transit of Mercury across the disk of the sun in the late 1990’s where Ron set up telescopes and spoke to students and the public about the transit at the University of La Serena. Ron participated in educational outreach efforts through his professional position at the observatory and through the Tucson Amateur Astronomy Association, of which he was an active member.
Ron is survived by his wife of 50 years, Judy Probst, and their children Matthew Probst and Elizabeth Probst of Tucson, Arizona.