The Submillimeter Array (SMA), an 8-telescope radio interferometer positioned close to the summit of Maunakea in Hawaii, reached an vital milestone early this 12 months. On January 26th, 2026, scientists from the Harvard & Smithsonian Center for Astrophysics (CfA) demonstrated this new alert system’s means to quickly reply to astronomical phenomena recognized by area telescopes. Inside minutes of a gamma-ray burst (GRB) being recognized, the SMA made the primary observations of such an occasion at millimeter and submillimeter wavelengths.
This adopted an automatic alert from NASA’s Neil Gehrels Swift Observatory, which detected a flash of gamma rays from a supply positioned about 1.8 billion light-years from Earth. Inside 90 seconds of detection, the system alerted the on-duty operator. Inside 13 minutes, the telescopes have been on course whereas a separate automated evaluation generated photos of the explosion in close to actual time. The whole course of occurred nearly completely with out human intervention, demonstrating the alert system’s means to slim the hole for millimeter/submilliter observations of transient occasions.
GRBs are essentially the most highly effective outbursts within the Universe, fast however extraordinarily energetic occasions which might be produced by relativistic jets – streams of charged particles touring at near the pace of sunshine. These jets are produced when large stars collapse (a supernova) or when compact objects, comparable to neutron stars, merge (a kilonova). They’re adopted by an afterglow that X-ray and optical telescopes have been in a position to monitor inside minutes and even seconds of an occasion.
Sadly, millimeter-wave telescopes have historically lagged on this respect.
Swift captured the afterglow of GRB 221009A, the brightest gamma-ray burst ever recorded, detected on October ninth, 2022. (Credit score: NASA/Swift)
Addressing that is of nice significance to astronomers, since it could yield helpful information on what accompanies GRBs. As they point out of their paper, which appeared in The Astrophysical Journal Letters, the interplay of relativistic jets with their setting produces a ahead shock (FS) propagating within the native medium, and a reverse shock (RS) propagating again into the ejecta. Because the FS emission is delicate solely to the explosion vitality, RS radiation stays key to finding out the jet’s composition, magnetization, and different properties.
Stated CfA astrophysicist Garrett Keating, the Deputy Director of the SMA, who led the rapid-response effort:
It was an unimaginable factor to look at in actual time. With the ability to react and course of information this rapidly is an enormous departure from how SMA normally operates, but it surely was completely vital for capturing an occasion the place minutes matter. This was the primary time we had the total system on-line. We discovered quite a bit from the expertise, and assume we will get the response time all the way down to as little as two to 3 minutes.
Two days later, observe‑up observations confirmed that the supply had light, an additional indication that the SMA had captured a transient afterglow moderately than a background supply of radiation. These observations marked the launch of the SMA Sub/millimeter Program to Quickly Examine Novel Time‑area Sources (SMA SPRINTS), which makes use of the SWA and its wideband improve (wSMA) to supply fast follow-up observations of transient occasions.
The response time on this case was roughly two orders of magnitude sooner than what’s typical for millimeter and submillimeter telescopes. This can be a large plus, on condition that conventional interferometry – the place mild from a number of observations is mixed to visualise phenomena which might be tough to detect – is time-consuming and doesn’t present astronomers with direct photos from a telescope. This new functionality, made attainable by the rapid-response system, is due to this fact a game-changer for the sphere.
Vera C. Rubin Observatory and the Milky Method Galaxy (Credit score: Rubin Observatory/NSF/AURA/B. Quint)
As new amenities, such because the Vera C. Rubin Observatory and the Nancy Roman House Telescope, start sending quite a few alerts, the wSMA will assist radio astronomers be able to seize such occasions. Stated co-author Tanmoy Laskar, an Assistant Professor of Physics and Astronomy on the College of Utah:
This new functionality opens a novel window into the physics behind a number of the strongest stellar explosions. With the SMA, we will now probe the construction and composition of the ejecta in unprecedented element, bringing us nearer to understanding how these explosions launch their highly effective jets.
Additional Studying: CfA, The Astrophysical Journal Letters.
