Steward Observatory's Dennis Zaritsky Receives University's Highest Faculty Honor

Steward Observatory Deputy Director Dennis Zaritsky was honored with the title of Regents Professor at the University of Arizona's 2025 Luminaries Outstanding Faculty Awards, held October 16 at the Stevie Eller Dance Theatre. The designation represents the highest faculty rank at the university and recognizes exceptional scholars who have achieved national and international distinction.

Zaritsky was one of three faculty members to receive the prestigious appointment, which is limited to no more than 3% of the university's tenured and tenure-track faculty members. With 46 current Regents Professors among 1,557 eligible faculty, the title serves as recognition of the highest academic merit and is awarded to those who have made unique contributions to the university's quality through distinguished accomplishments in teaching, scholarship, research, or creative work.

An observational astronomer specializing in galaxy structure and evolution, Zaritsky is recognized as one of the most innovative thinkers and researchers in his field. His groundbreaking work includes using dwarf galaxies to map the distribution of dark matter in the Milky Way and other galaxies.

Among his most influential contributions, Zaritsky co-authored the paper "A Direct Empirical Proof of the Existence of Dark Matter" and a set of four papers providing the first maps showing the stars and dust in the two largest satellite galaxies of the Milky Way: the Small Magellanic Cloud and Large Magellanic Cloud.

His achievements have earned numerous accolades, including the 2024 Beatrice M. Tinsley Prize from the American Astronomical Society, awarded biennially for outstanding research contributions to astronomy or astrophysics. He also received the society's 1999 Newton Lacy Pierce Prize for outstanding achievement in observational astronomical research by a scientist under 36 years old, and a 2006 John Simon Guggenheim Foundation Fellowship.

Reflecting on when he knew astronomy was his calling, Zaritsky recalled a transformative undergraduate experience. "It was during my first research project as an undergraduate. I got to go to a telescope for the first time," he shared in remarks before the ceremony. "When you realize that you're doing something where you're the first person to actually see something or think about something, it's just so inspiring that you're trying to advance knowledge—then I knew that that's what I wanted to do."

Beyond his research accomplishments, Zaritsky expressed deep appreciation for the University of Arizona's commitment to maintaining a world-class astronomy program. "I love the University of Arizona. I was here as a grad student, came back as faculty," he said. "Just the fact that they've managed to support this incredible astronomy program that I'm part of attracts people from around the world."

That global draw is a source of ongoing inspiration for him. "I'm always inspired when we have people fly halfway across the world to study with us. It's inspiring to see people have such a vote of confidence in the University and what we can do for them and their careers."

In addition to his teaching and research responsibilities, Zaritsky serves as deputy director of Steward Observatory and recently completed a six-year term as chair of the Giant Magellan Telescope Science Advisory Council.

The 2025 Luminaries Awards ceremony honored 30 faculty members across various categories for groundbreaking research, service to the community, and excellence in teaching and mentoring. "Today, we honor and celebrate faculty excellence," said Provost and Chief Academic Officer Patricia Prelock at the ceremony. "We are proud to have outstanding faculty here at the University of Arizona, leaders in their fields, both nationally and internationally, who generously share their time, their talent and expertise to elevate teaching and learning across our campus."

Zaritsky's appointment as Regents Professor stands as a testament not only to his scientific achievements but also to his dedication to advancing knowledge and inspiring the next generation of astronomers at one of the world's premier research institutions.