The universe is vast, but astronomers don’t have to look too far to find something genuinely new. Researchers at the Center for AstroPhysical Surveys (CAPS) used the South Pole Telescope to probe one of the most complex regions of the sky, the crowded inner Milky Way, and uncovered powerful, short-lived bursts of millimeter-wavelength light from two known accreting white dwarf systems. In a region where overlapping sources, dust, and confusion can make discovery difficult, these flashes stood out clearly and point to a class of energetic events that millimeter surveys are uniquely positioned to reveal.
The events, reported in a recent paper in The Astrophysical Journal, represent the first time such flares have been discovered in a wide-field, time-domain millimeter survey. That distinction matters: rather than targeting a pre-selected list of candidate objects, the survey repeatedly scanned a large swath of the Galactic Plane and caught the flares serendipitously. The result demonstrates that high-cadence millimeter mapping can do more than measure static emission. They can also detect fast, rare transients and open a new observational window on the dynamic astrophysics of the Milky Way’s central environments.
“We’re just starting to understand what’s possible,” said Yujie Wan, lead author of the study and graduate student in the Department of Astronomy at the University of Illinois Urbana-Champaign. “There is so much happening at the center of our galaxy that we’ve never been able to observe at these wavelengths. This discovery is the first step toward a much richer picture of the Milky Way.”