Liam Dubay

About Me

I'm a final-year astrophysics PhD student at The Ohio State University. I study the chemical evolution of our Milky Way Galaxy and the astrophysical origin of the elements with my advisor, Prof. Jennifer Johnson. I'm on the leadership team for the Polaris program, and I'm also a planetarium presenter at OSU.

Originally from Portland, Oregon, I graduated from Whitman College in 2021 with a BA in astrophysics and music performance. In my spare time I enjoy rock climbing, film photography, and playing the cello.

My Research

I want to understand how the Milky Way—the galaxy we call home—has evolved over its 13 billion-year lifetime. I also want to understand the astrophysical processes that produce the elements around us, from the oxygen we breathe to the iron in our blood. To do this, I study galactic archaeology, which means that I use the stars that make up our Galaxy as a fossil record that traces its evolution over time. I use large stellar spectroscopic surveys such as APOGEE and Milky Way Mapper combined with galactic chemical evolution models to unravel the history of the Milky Way and the origin of the elements.

In Dubay et al. (2024) I showed that the stellar explosions that produce much of the Galaxy's iron, called Type Ia supernovae, must enrich the Galaxy on longer timescales than previously thought in order for chemical evolution models to match the data. In Dubay et al. (2026) I showed that major gas accretion events (and in particular the "two-infall model" of our Galaxy's evolution) are inconsistent with the Milky Way's stellar record. My current research focuses on the origin of heavy elements such as cerium in Asymptotic Giant Branch stars, and whether these elements may be used as "chemical clock" to estimate the ages of stars.

Recent Publications