Tucson doctor wins national award for his second act as amateur astronomer

After a high-stakes career as a pediatric cardiologist, Richard Donnerstein has chosen to spend the time he has left staring off into space.

In 2008, the newly retired Tucson medical doctor enrolled in an introductory astronomy class at Steward Observatory. He would eventually work his way through the entire course catalog for an undergraduate degree in the field, then convince one of his professors to take him on as a researcher.

“After I retired, I obviously had to find something to do, and I'm way too uncoordinated to play golf,” Donnerstein said. “University of Arizona has one of the premier astronomy departments in the world, so I decided to take some courses, and I just loved it.”

Sixteen years and about two dozen scientific publication credits later, the 82-year-old’s post-retirement hobby has earned him a prestigious national award for amateur astronomy.

On Jan. 16, the American Astronomical Society named Donnerstein as this year’s recipient of the Chambliss Amateur Achievement Award for his “significant contributions” to the detection of some of the faintest and most confounding galaxies in the universe.

Donnerstein was recognized for his work on a U of A-led project called Systematically Measuring Ultra-Diffuse Galaxies, or SMUDGes for short.

“That's exactly what they look like. They look like a smudge, you know, like somebody left a fingerprint on a photograph,” he said.

Donnerstein developed a computer algorithm capable of identifying these faint objects in images collected during massive surveys of the entire night sky above both the Northern and Southern hemispheres.

“These particular galaxies are interesting because they can be quite big. They can be the size of the Milky Way, but only have maybe 1 percent of the amount of stars, so they're really quite faint,” he said. “We basically started looking for them and found over 7,000 of these things spread everywhere.”

Their existence raises a host of questions astronomers are still trying to answer, Donnerstein said. “Why are they here? How do they form? What holds them together? By having enough of them (to study), we can do some statistical analysis and get a rough idea of why they're there and why they haven't fallen apart.”

Westward bound

Donnerstein was born in New York and raised in South Florida. He went to New York University for medical school and Yale University for his residency and fellowship, before joining the Army and serving four years as a pediatric cardiologist at Walter Reed hospital in Bethesda, Maryland.

The self-described “die-hard Easterner” joked that he barely knew where Arizona was in 1985, when he landed a job at what was then called University Medical Centerin Tucson.

“They had a superb pediatric cardiology program. At that time, it was probably one of the world's leading places for research on echocardiography,” he said. “The job perfectly fit what I was looking for.”

He’s been here ever since.

Donnerstein said there is “very little” similarity between the work he did as a heart doctor and what he does now as an amateur astronomer.

“That is why I’m doing it, I think. I enjoyed my career, and I certainly miss many, many of my patients, but when I retired I looked to do something as far away from medicine as possible,” he said.

As it turns out, trying to unlock the mysteries of the cosmos is a lot less stressful.

“You don't have to worry about bad decisions. If you're off by a factor of 10, nobody cares,” Donnerstein said with a laugh.

The computer programming stuff came naturally to him, he said, because he studied engineering before he went to medical school and has been working with computers since the days of punch cards.

“As a matter of fact, I was doing it even prior to punch cards, when we were just pushing buttons on machines,” Donnerstein said.

His research focus in medical school was on using computers to analyze heart sounds.

To help sift out the SMUDGes in a universe filled with billions of other galaxies, Donnerstein said he borrowed a machine-learning program first built for “telling cats from dogs from monkeys from elephants, that sort of thing.”

“It was an algorithm designed to actually discriminate between various types of images,” he explained. “I adapted that for galaxies, and it worked quite well.”

'Secret sauce'

The quest to catalog and study ultra-diffuse galaxies is being led by another award-winning local astronomer. Dennis Zaritsky is deputy director of the U of A’s Steward Observatory and principal investigator for the SMUDGes Project. He has also served as Donnerstein’s research advisor for the past decade or so.

Last year, the American Astronomical Society awarded Zaritsky the coveted Beatrice M. Tinsley Prize for what it described as his “innovative observations probing the structure and evolution of galaxies.”

 

Zaritsky in turn nominated Donnerstein for this year’s Chambliss prize.

One glowing letter of support for that nomination came from U of A professor and astronomer David Sand, who recently began working with Donnerstein on a similar computer-driven search to help identify some of the faintest dwarf galaxies in the nearby universe.

Sand said the “secret sauce … blended by Richard” has already paid off, producing dozens of strong candidate galaxies for further study.

“Richard’s enthusiasm is contagious, and his scientific impact formidable. I have never experienced an amateur with his skill set, passion and work ethic before,” Sand wrote in his letter to the astronomical society. “He is showing once again his mastery of algorithms at scale applied to a project that will shed light on the nature of dark matter and the floor of galaxy assembly.”

The award came as a complete surprise to Donnerstein, who said the prize comes with a silver medal and an invitation to an upcoming meeting of the astronomical society this summer in Alaska or next January in Phoenix.

“I’m very flattered, very honored at my age to be able to (receive) that,” he said. “The kids and grandkids are impressed, if nothing else.”

Ultimately, though, Donnerstein is just glad to have found something to do in retirement that challenges him and makes him feel useful.

“It's a win all the way around, actually. They obviously get free help, and, from my standpoint, I've learned so much and it’s kept me very busy and occupied,” he said.

And unlike an expensive hobby like golf or restoring old cars, all astronomy costs him is time.

“Working for nothing is still less expensive than what it could have been,” Donnerstein said.

Read the full article in the Arizona Daily Star

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U of A's Rieke recognized

One of the University of Arizona’s top professional astronomers also collected some hardware this year from the American Astronomical Society.

U of A Regents Professor Marcia Rieke was selected for the 2025 Henry Norris Russell Lectureship in celebration of her “career of eminence in astronomical research.”

According to the society, Riecke was recognized for “her fundamental contributions to infrared astronomy in space and on the ground,” especially the central role she played in the development of the James Webb Space Telescope and its primary Near InfraRed Camera, which she helped design, build and deploy.

She continues to direct the operation of the instrument as its principal investigator.

Rieke’s latest award comes with an all-expenses-paid invitation to deliver a lecture at a future society meeting and have it published in a society journal.

Last year, she won the Cosmology Prize — and a $500,000 award — from the nonprofit Gruber Foundation for her work on the Webb Telescope and other contributions to astronomy.

Rieke joined the U of A faculty in 1975 and now holds the Dr. Elizabeth Roemer Endowed Chair at Steward Observatory. She was elected to the National Academy of Sciences in 2012.