International astronomers, including Rice University’s Andrea Isella and Charlie Gardner, have unveiled highly detailed images of planets forming around young stars. The discovery is part of the exoALMA project, which uses the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to peer into the dusty disks where new worlds are born.
Unlike traditional planet-hunting techniques that rely on light from planets themselves, exoALMA looks for disturbances in the surrounding gas and dust, signatures of planetary formation. The results were published in a special issue of The Astrophysical Journal Letters, featuring 17 papers with more expected.
“This initiative represents a new era in planet hunting,” said Isella, the William V. Vietti Associate Professor in Space Physics. “We’re observing the cosmos with unprecedented precision to understand how worlds are born.”
By combining signals from 66 high-powered antennas, ALMA enabled the team to resolve spirals, rings and gaps, all features shaped by forming planets. To interpret the data, the researchers developed custom image-processing techniques to remove noise and align observations taken over time.
The team tracked key molecules to study the movement and density of gas within 15 young star systems. Their analysis revealed vertical structures and subtle shifts in rotation, or signs that pressure changes are helping corral dust into rings, an early step in planet formation.
They also introduced a new method for estimating how much material is available to build planets, offering a more complete picture of the birth environments of solar systems like ours.
“These disks are far more dynamic than we imagined,” Isella said. “We’re seeing evidence of gravitational interactions, instabilities and the early influence of planets before they’re fully formed.”
Gardner, a graduate student studying under Isella’s mentorship, contributed by analyzing ALMA data using theoretical models developed with Los Alamos National Laboratory. His role underscores exoALMA’s focus on early career leadership and interdisciplinary research.
Gardner’s research centers on LkCa 15, a circumstellar disk thought to harbor planets larger than Jupiter in the process of forming. However, new ALMA observations of carbon monoxide emission and Gardner’s analysis suggest a different story. The observations reveal unexpectedly high levels of carbon monoxide, which is inconsistent with the presence of massive planets, casting a fresh mystery on the nature of this system.
“Applying cutting-edge models to real data has advanced my research skills and deepened my understanding of how planets form in these complex environments,” Gardner said.
Members of the exoALMA project plan to continue expanding the survey and refining their detection methods. All data and imagery will be publicly available, ensuring the work benefits the broader astronomical community.