NASA’s Fermi, Swift Capture Revolutionary Gamma-Ray Burst
Watch to learn how an event called GRB 211211A rocked scientists’s understanding of gamma-ray bursts – the most powerful explosions in the cosmos.
Credit: NASA’s Goddard Space Flight Center
Music Credits: "Finished Plate" by Airglo and "Binary Fission" by Tom Kane
Watch this video on the NASA Goddard YouTube channel.
On Dec. 11, 2021, NASA’s Neil Gehrels Swift Observatory and Fermi Gamma-ray Space Telescope detected a blast of high-energy light from the outskirts of a galaxy around 1 billion light-years away. The event has rattled scientists’ understanding of gamma-ray bursts (GRBs), the most powerful events in the universe. This burst is called GRB 211211A.
For the last few decades, astronomers have generally divided GRBs into two categories. Long bursts emit gamma rays for two seconds or more and originate from the formation of dense objects like black holes in the centers of massive collapsing stars. Short bursts emit gamma rays for less than two seconds and are caused by mergers of dense objects like neutron stars. Scientists sometimes observe short bursts with a following flare of visible and infrared light called a kilonova.
Fermi and Swift detected GRB 211211A simultaneously. Swift was rapidly identified its location in the constellation Boötes, enabling other facilities to quickly respond with follow-up observations. The combined data show not only a burst lasting 50 seconds but also a kilonova – the first time both phenomena have been documented in the same event. The data have also provided the earliest look yet at the first stages of a kilonova.
Many research groups have delved into the observations collected by Swift, Fermi, the Hubble Space Telescope, and others. Some have suggested the burst’s oddities could be explained by the merger of a neutron star with another massive object, like a black hole.
The light following the burst, called the afterglow emission, also exhibited unusual features. Fermi detected high-energy gamma rays starting 1.5 hours post-burst and lasting more than 2 hours. These gamma rays reached energies of up to 1 billion electron volts. (Visible light’s energy measures between about 2 and 3 electron volts, for comparison.)
Two neutron stars begin to merge in this illustration, blasting a jet of high-speed particles and producing a cloud of debris. Scientists think these kinds of events are factories for a significant portion of the universe’s heavy elements, including gold.
Credit: A. Simonnet (Sonoma State Univ.) and NASA’s Goddard Space Flight Center
Gamma-ray burst 211211A, the location of which is circled in red, erupted on the outskirts of a spiral galaxy around 1 billion light-years away in the constellation Boötes. The NASA/ESA Hubble Space Telescope captured the image with its Wide Field Camera 3 and Advanced Camera for Surveys.
Credit: NASA, ESA, Rastinejad et al. (2022), and Gladys Kober (Catholic Univ. of America)
A broader view of GRB 211211A’s location, circled in red, captured using three filters on Hubble’s Wide Field Camera 3.
Credit: NASA, ESA, Rastinejad et al. (2022), Troja et al. (2022), and Gladys Kober (Catholic Univ. of America)
Astronomers suspect that most short-duration gamma-ray bursts originate from merging systems containing neutron stars, objects more massive than the Sun but as small as a city. In this illustration, a brief blast of gamma rays (magenta) arises from jets launched when the objects collide.
Credit: NASA’s Goddard Space Flight Center
GRB 211211A was an unusual gamma-ray burst. Its initial flare of gamma rays lasted nearly a minute, and it was followed by a kilonova. It doesn’t fit neatly into the two categories scientists typically use for these bursts. As shown in this illustration, some researchers think this event could be the result of the merger of a black hole and a neutron star.
Credit: NASA’s Goddard Space Flight Center
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NASA's Goddard Space Flight Center. However, individual items should be credited as indicated above.
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Producer
- Sophia Roberts (Advocates in Manpower Management, Inc.)
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Science writers
- Jeanette Kazmierczak (University of Maryland College Park)
- Francis Reddy (University of Maryland College Park)
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Artist
- Aurore Simonnet (Sonoma State University)
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Animator
- Scott Wiessinger (KBR Wyle Services, LLC)
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Technical support
- Aaron E. Lepsch (ADNET Systems, Inc.)
Release date
This page was originally published on Wednesday, December 7, 2022.
This page was last updated on Wednesday, September 6, 2023 at 10:29 AM EDT.