Peter Pesch (1934-2024)

Peter Pesch, Emeritus Professor of Astronomy at Case Western Reserve University, died at the Judson Manor retirement community in Cleveland, Ohio on Tuesday, July 16, 2024. He was 90 years old.

Peter was born to Roland and Hildegard Pesch (nee Stoecklin) June 29, 1934 in Zürich, Switzerland. His father was a leather craftsman and leather factory manager and an amateur flutist. His mother was a pianist, artist and occupational therapist. His parents were involved in the leftist resistance to Hitler and hid people who were fleeing Germany in their apartment in Zürich. 

It was the true but awful news they heard from those they sheltered that led them to emigrate to the United States in 1939. They lived on the south side of Chicago, IL and became US citizens in 1944. Peter started high school there, but in late 1950 the family moved to Rio Piedras, Puerto Rico where Roland managed a leather factory. Despite having to learn a second new language, Peter finished high school there in 1951 and enrolled in math and physical science courses for two years at the University of Puerto Rico.

He returned to Chicago in 1953 enrolling at the University of Chicago and earning B.S. and M.S. degrees in physics in 1955 and 1956, respectively. Two of his fellow students and life-long friends were Donat Wentzel, born just 4 days earlier also in Zürich, and Carl Sagan. Like them, Peter stayed at Chicago for his Ph.D. which was awarded in 1960 for the thesis “Photometric studies of three galactic clusters containing probable supergiant members of intermediate spectral type”; his adviser was W. Albert Hiltner. He credited Kevin Prendergast as another important mentor.

In 1960 Peter accepted a post-doctoral fellowship at Case Institute of Technology (Case Western Reserve University (CWRU) after its merger with Western Reserve University in 1967) in Cleveland, , home of the Warner and Swasey Observatory. He became an assistant professor of astronomy a year later. There was no undergraduate astronomy degree awarded until 1962, but interested students could take astronomy courses as electives, and Peter taught some of these and a senior seminar. He was popular with the students, and several went on to enroll in graduate programs and have successful careers in astronomy. For a few semesters he taught introductory physics as well.

The main research telescope was the Burrell 61/91-cm Schmidt with two objective prisms. Peter continued his work on galactic clusters and was now able to add spectral types to his UBV photometry done with the 91-cm telescope of the McDonald Observatory. He took particular interest in the Pleiades cluster and did deep searches for M dwarfs and flare stars with the Schmidt. Despite taking many plates looking for Pleiades flare stars, he found none whereas I (DJM) found one in the much younger Cep OB4 association after a few hours of exposure. When informed of this, Peter passed me in the hall one day muttering “You pr…!” – an example of his piquant sense of humor.

He discovered CaOH in the spectra of late M dwarfs in 1972, the first triatomic molecule found in a stellar atmosphere. His interests in stellar astronomy varied widely, and he made contributions to galactic structure via surveys for early-type stars.

Starting about the mid-1970s he collaborated extensively with Nicholas Sanduleak on several photographic objective-prism surveys until Nick’s untimely death in 1990. One such well-cited survey was the search for emission-line galaxies in Boötes where previous studies seemed to show a lack of galaxies with luminosities comparable to that of M31. They found 424 galaxies within the suspected void thus questioning its reality.

Another major survey the pair undertook was the Case Low-Dispersion Northern Sky Survey published in 15 installments from 1983 to 1995 in the ApJ Supplement Series; after Sanduleak’s death, C. Bruce Stephenson and DJM were brought onto the project. Eight categories of objects were noted ranging from emission-line galaxies and stars, field horizontal-branch stars, to faint carbon and late M halo giants. The survey sparked many follow-up studies by other researchers.

Peter was promoted to associate professor in 1970 and to full in 1975 when he became chairman of the astronomy department and director of the Warner and Swasey Observatory, a position he held until his retirement in 1997. He spent a sabbatical year 1970-71 at Kitt Peak National Observatory obtaining photoelectric photometry and slit spectra of many of the peculiar stars found on the Case objective-prism plates. By the late 1970’s light pollution from Cleveland and its suburbs made it increasingly difficult to carry out programs with a wide-field telescope, so in 1979 the Burrell Schmidt was moved from its site near Chardon, , 30 miles east of Cleveland, to a new dome on Kitt Peak. Peter was in charge of the move and for improvements to its mechanical and optical properties; funding was provided by the National Science Foundation and the Cleveland Astronomical Society. The telescope had been moved once before, in 1957, from East Cleveland to near Chardon for the same reason with Dr. Victor Blanco in charge then. (Victor was Puerto Rican and had a close bond with Peter.)

Peter took his responsibilities as a scientist and educator seriously – refereeing papers submitted to the journals, writing book reviews, and serving on a number of NASA ADP and IUE proposal panels. He was the thesis adviser for four Ph.D. students. One student wrote the following:

Peter was my Ph.D. dissertation adviser from 1976 through 1978. He was a friendly, low-key mentor who was always willing to provide assistance when requested. The initial phase of my research involved taking several dozen one-hour, guided exposures with the Burrell Schmidt telescope. Peter graciously offered to assist in taking some of these plates. Following one of his nights, I arrived at the observatory to find a note on the bulletin board which stated, “Always Develop Your First Plate!” Peter had taken eight plates during the night with the telescope dust cover still in place! I enjoyed my time working with Peter and have fond memories of our time together.

Peter was president 1976-84 of the Cleveland Astronomical Society, an amateur-professional organization founded by Cleveland’s “father” of 20^th-century astronomy, Dr. Jason J. Nassau in 1922, and source of funding for many observatory programs. He took a leave of absence from CWRU in 1984-86 to serve as an NSF program officer in Washington, DC.

Normally mild-mannered and discreet, nothing could set him off as much as pseudoscience and claims of the paranormal. When author Robert K. G. Temple wrote The Sirius Mystery (St. Martin's Press, 1975), claiming that the Dogon people of Mali, a pre-industrial culture, were made aware of the white dwarf Sirius B by extraterrestrial visitors, Peter and half-brother Roland Pesch pounced and published a devasting debunking article in The Observatory 97, 26, 1977. Theirs was one of several such criticisms on various grounds; other critics were James Oberg, Ian Ridpath, and Peter’s college friend Carl Sagan.

In the spring of 1983, Peter arranged to have one of his Chicago professors, the renowned Subrahmanyan Chandrasekhar, come to Cleveland to lecture and receive a prestigious CWRU award. Peter was a perceptive ‘talent scout’; six months later ‘Chandra’ was awarded half of the Nobel Prize in Physics for his contributions to stellar structure.

Peter was as active in retirement as he was during his career. He loved to travel and spoke several languages. He visited Europe often to visit daughter Ada, first concertmaster of the Philharmonia Zürich, as well as Chile, Cuba, Mexico, Scandinavia, and Indonesia. Physically active, he enjoyed swimming, bicycling, ice skating, skiing, dancing, kayaking, hiking and camping. 

He and wife Donna moved to Judson Manor retirement community adjacent to the CWRU campus in 2016. They loved the community and activities offered there. Peter often gave informal lectures on astronomy and other topics to its residents and was a cherished member of the Manor.

After retirement, Peter built a wooden kayak and enjoyed prolific jewelry and pottery making. He was an aficionado of Jaguar automobiles; at one time he owned four of them and did his own servicing. In the southern summer of 1999-2000 he spent several months on the ice in Antarctica on a CWRU-sponsored expedition as a volunteer meteorite-gatherer.

Peter was an active volunteer. He and Donna spent countless hours at the Cleveland Museum of Natural History giving wild animal shows to visitors (see photo) and cataloging for the Ornithology and Vertebrate Divisions.  He conducted trash-pickup walks near the grounds of Judson Manor and tutored math at the Intergenerational School, a sponsored school of the Cleveland Metropolitan District.   

Organizations to which he was devoted include the Cleveland Astronomical Society, the Cleveland Museum of Natural History, Ecophilia, and The Nature Conservancy.  

Peter is survived by his wife of 49 years, Donna Marie Lehmann Pesch of Judson Manor, Cleveland. He is survived by daughters Marina Pesch Ergun of Pepper Pike, and Ada Pesch of Zürich, Switzerland and by their mother, Vidya Sendra, of Mayfield Village, Ohio. Also survived by sister Tina Lane of San Miguel de Allende, Mexico and half-brother Roland Pesch of Sea Ranch, CA. His descendants include grandchildren Ayden, Erin, Aliye, and Isabel and great-grandchildren Olivia, Liam, Benjamin, Lucas, Tessa and Domenico.

AstroGen link: https://astrogen.aas.org/front/searchdetails.php?agnumber=4346