Making an impact in astronomy

Cassandra Hall, assistant professor of astrophysics, has focused in on planet formation outside our Solar System and advanced the compelling idea of a “photosynthetic habitable zone” that could help narrow down the search for life on other planets.

With a cluster of research papers that have made a big impact in astronomy, Hall has added to a re-thinking of the cosmos:

Over her last several trips around the Sun, Cassandra Hall’s eye has been trained on AB Aurigae—or, more accurately, on a disk-shaped cloud of swirling dust orbiting around it. The cloud contains an embryonic planet, perhaps more than one, its massive, spiral-shaped arms coalescing on a cosmic time scale into something(s) more discrete.

It’s this process of planet formation that has Hall looking heavenward. The evidence she and her colleagues have collected suggests that the circumstellar disk dancing around AB Aurigae is transforming not through the canonical theory of core accretion—bits of space rock slowly accumulating into progressively larger bodies—but a long-theorized process called gravitational instability (GI).

...

Hall is a computational astrophysicist. She applies for time at telescopes like the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama Desert of northern Chile—time that is awarded very competitively to astronomers worldwide—then runs the collected data through supercomputers to analyze and conduct simulations of cosmic events. Until the Nature paper, that’s all GI researchers had to go on: simulations.

“When I first started working on gravitational instability in 2013, it was kind of considered—I don’t want to say a fringe theory, because that’s not true,” said Hall, assistant professor of computational astrophysics in the Franklin College of Arts and Sciences Department of Physics and Astronomy. “It was like it was acknowledged that it was important, but it had never been definitively observed.”

Read the entire feature by our colleagues in Research Communications.

Image: still photo from Hall's TEDxUGA presentation From Darkness to Discovery: The AI Hunt for Hidden Forming Exoplanets