New Rapid-Response Capability Allows SMA to Catch Gamma-Ray Burst Within Minutes
MAUNAKEA, HAWAII – On January 26, 2026, the Submillimeter Array (SMA) achieved a groundbreaking milestone in astrophysics by observing a gamma-ray burst (GRB) at millimeter and submillimeter wavelengths just minutes after its discovery. This marks the earliest such observation ever recorded at these frequencies.
"Getting data minutes after an explosion is a new capability." – Tanmoy Laskar, University of Utah
How It Worked
The SMA was triggered by an automated alert from NASA's Swift Observatory. The response sequence was remarkably fast:
- Within 90 seconds, the operator was alerted.
- Within 4 minutes, the telescope began moving.
- Within 13 minutes, observations started.
- Automated analysis produced near-real-time images.
The response time is about 100 times faster than typical for millimeter/submillimeter telescopes.
Confirming the Transient
Follow-up observations taken two days later showed that the source had faded significantly, confirming it was a transient afterglow—the fading emission from a gamma-ray burst.
What This Means for Astronomy
GRBs are incredibly bright explosions resulting from the collapse of massive stars or the merger of neutron stars. While their afterglow is typically observed at X-ray and optical wavelengths quickly, millimeter-wave telescopes have historically lagged far behind.
This new capability closes that gap.
"This was the first full system test; response time could be reduced to 2–3 minutes." – Garrett Keating, CfA
The SMA's new rapid-response system is part of the SMA SPRINTS program, which aims to support rapid follow-up of transient events. This capability will be crucial for future facilities like the Rubin Observatory's Legacy Survey of Space and Time (LSST) and the Roman Space Telescope.
"The SMA's new capability is a gamechanger," said Edo Berger of Harvard.
Ranjani Srinavasan of the SMA noted that interferometry usually does not produce direct images quickly, making this real-time imaging achievement particularly significant.