Dr. Carolyn Kierans, a research astrophysicist at NASA's Goddard Space Flight Center, is an expert in the study of antimatter and its signatures in our galaxy. Her work focuses on the 'MeV gap', a band of medium-energy gamma rays that is one of the least-explored windows in astronomy. This gap is particularly fascinating because it reveals some of the universe's most energetic processes, from exploding stars to the environments around black holes. However, it is also stubbornly hard to look there, as gamma rays cannot be focused by telescopes and require large, heavy particle detectors to be caught and reconstructed.
Dr. Kierans' journey into astronomy was not a straightforward one. She grew up in Canada with a mother who taught math, and a household where numbers were never intimidating. She initially assumed she would become a physics teacher, following in her mother's footsteps. However, a summer co-op placement at Canada's national particle physics laboratory, TRIUMF, sparked her interest in research. She discovered that what excited her most was not the theory itself, but the process of building and testing instruments.
Her PhD at UC Berkeley focused on the strange art of seeing gamma rays. She helped fly an instrument called COSI on a NASA super-pressure balloon, which captured the galaxy's 511 keV antimatter glow with a new kind of telescope for the first time. This success helped COSI graduate from a balloon experiment into a full NASA satellite, scheduled to launch in August 2027. Dr. Kierans is now working on its data pipeline.
Dr. Kierans' talk at the 248th meeting of the American Astronomical Society will be about a prototype called ComPair, the mission she leads as Principal Investigator. This mission was flown from Fort Sumner, New Mexico in 2023 to prove the technology for a future mission that could finally cover the entire MeV gap. Her talk will also be a tribute to the instrument-builders and pipeline-writers whose careers make science possible, and an invitation to the next generation of astronomers.
Dr. Kierans' advice to students thinking about grad school is specific. She says, 'Grad school is tough, but not in the way most people expect. Classes are hard, sure, but the most challenging part is learning to do self-guided research, balancing the workload, and convincing yourself you truly belong there with your seemingly more brilliant peers. Hard work and perseverance outweigh brain cells.' For young women who love physics but wonder whether they belong, her advice is more personal. She says, 'Find a mentor, ideally one who looks like you'.
One thing Dr. Kierans wants to make sure readers hear is that we celebrate telescopes for the images and discoveries they deliver, but we rarely hear about the years of unglamorous building that came first. She believes that behind every great observatory is a long lineage of graduate students and postdocs who soldered, calibrated, and coaxed the hardware into working and who often grow into the leaders of the next mission. Her talk will be an invitation to the next generation of astronomers, who might be reading this article right now.
