Discovery of Oldest Stars in Universe Demonstrates UToledo Research Excellence

Discovery of Oldest Stars in Universe Demonstrates UToledo Research Excellence

When Ryan Hazlett began his doctoral studies at The University of Toledo in 2020, it wasn't a given that astronomers would ever do more than theorize about the first stars to have formed in the aftermath of the Big Bang.

But a lot has changed in his time as a Rocket.

Hazlett is now preparing to defend his dissertation as a collaborator on a groundbreaking article proposing the first direct detection of these stars - a discovery made possible thanks to the unprecedented capabilities of the James Webb Space Telescope.

"We're finally able to see what we predicted with our models," Hazlett said.

Astronomy and astrophysics are an area of research excellence at UToledo, recognized as one of the country's top-tier research universities through the prestigious R1 Classification in the latest Carnegie Classification of Institutions of Higher Education, and faculty and student researchers routinely engage with some of the most advanced terrestrial observatories and space-based telescopes in the world.

These include the James Webb Space Telescope, on which UToledo astronomers have led at least one research project on each cycle of scheduled observing time since it launched as the latest and greatest in infrared technology in 2021. This means UToledo astronomers are directly contributing to an ongoing revolution in how we understand the universe around us.

Hazlett, who is pursuing a doctorate in physics with a concentration in astrophysics, works closely with Dr. Eli Visbal, who, as an associate professor and theoretical astronomer, specializes in numerical simulations and theoretical models that help his observational colleagues around the world understand what they see using telescopes like Webb.

With a particular interest in the cosmic origins of the universe, Hazlett and Visbal had already dedicated years to models related to the category of stars known as Population III by the time they came across Webb observations of the galaxy LAP1-B.

Population III stars have long been theorized to have a chemistry low in heavy elements that astronomers call metals, for example, and a massive size that would dwarf our sun, a Population I star that formed much later and under a much different environment.

Ready to compare observational data to theory, the astronomers analyzed the stars in LAP1-B in relation to models designed to predict how the unique hydrogen-and-helium environment that made up outer space more than 13 billion years ago influenced the formation and characteristics of the first stars in the universe.

"LAP1-B was the perfect test case," Hazlett said. "We were able to run it through our models pretty quickly, and what we had predicted matched up with this observation."

Hazlett, Visbal and Dr. Greg Bryan, an astronomy professor at Columbia University, published their research proposing the first direct detection of Population III stars in the Astrophysical Journal Letters.

It's since generated significant attention in outlets like Space.com, Sky & Telescope and Dr. Neil deGrasse Tyson's StarTalk, reflecting the value of these stars to astronomers for several reasons beyond mere novelty.

"Population III stars help us understand our cosmic origins as the building blocks of early galaxies that ultimately evolved into modern-day galaxies like our Milky Way," Visbal said. "They might also help us to understand the nature of dark matter, which is one of the biggest mysteries in astronomy and physics."

Visbal echoed his student in describing their findings as exciting - even allowing for the possibility that future analysis will ultimately challenge their conclusion.

"We've been working on theoretical models of these stars for a long time," Visbal said. "So to now be on the precipice of perhaps direct detections is very exciting."