The Submillimeter Array (SMA), an 8-telescope radio interferometer located near the summit of Maunakea in Hawaii, reached an important milestone early this year. On January 26th, 2026, scientists from the Harvard & Smithsonian Center for Astrophysics (CfA) demonstrated this new alert system's ability to rapidly respond to astronomical phenomena identified by space telescopes. Within minutes of a gamma-ray burst (GRB) being identified, the SMA made the first observations of such an event at millimeter and submillimeter wavelengths.
This followed an automated alert from NASA's Neil Gehrels Swift Observatory, which detected a flash of gamma rays from a source located about 1.8 billion light-years from Earth. Within 90 seconds of detection, the system alerted the on-duty operator. Within 13 minutes, the telescopes were on target while a separate automated analysis generated images of the explosion in near real time. The entire process happened almost entirely without human intervention, demonstrating the alert system's ability to narrow the gap for millimeter/submilliter observations of transient events.
GRBs are the most powerful outbursts in the Universe, rapid but extremely energetic events that are produced by relativistic jets - streams of charged particles traveling at close to the speed of light. These jets are produced when massive stars collapse (a supernova) or when compact objects, such as neutron stars, merge (a kilonova). They are followed by an afterglow that X-ray and optical telescopes have been able to track within minutes or even seconds of an event.
Unfortunately, millimeter-wave telescopes have traditionally lagged in this respect.
Addressing this is of great importance to astronomers, since it would yield valuable data on what accompanies GRBs. As they indicate in their paper, which appeared in The Astrophysical Journal Letters, the interaction of relativistic jets with their environment produces a forward shock (FS) propagating in the local medium, and a reverse shock (RS) propagating back into the ejecta. Since the FS emission is sensitive only to the explosion energy, RS radiation remains key to studying the jet's composition, magnetization, and other properties.
Source: Universe Today
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