// SPACE.COM — SPAZIO & SCIENZA
Record breaker! Astronomers spot powerful cosmic explosion that lasted 27 days
"We don’t know what the central engine driving this outburst is, and that’s what makes this such a compelling event."
When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.
Astronomers have spotted a remarkable gamma-ray burst (GRB) that's a real Incredible Hulk compared to other cosmic explosions of the same type.
What makes this GRB so special is the fact that the central engine powering it remained active for around 27 days, flaring in X-rays following the initial blast. That's 20 days longer than the longest previous GRB on record.
This record-breaking burst — which is designated GRB 220706A and was spotted on July 6, 2022 — is even more exciting because scientists don't know what the central engine powering it actually is.
"In a nutshell, GRB 220706A is an extremely late X-ray flare. X-ray flaring is common following GRBs, but previously it has always come within the first few days after we detect the burst," study team member Benjamin Gompertz, of the University of Birmingham in England, told Space.com.
"The fact that we see flaring at around 27 days in the GRB’s rest frame tells us that there’s an ongoing active process, and that’s unprecedented in the known population," Gompertz added. "The previous record for delayed flaring was about six days after the GRB."
GRBs are some of the most powerful explosions in the cosmos. They have been linked to the collapse of a massive star, which also triggers a supernova and creates a black hole. This results in a long-duration GRB, while short-duration GRBs are thought to be triggered when two stellar remnants called neutron stars collide.
GRB 220706A is an example of an ultra-long GRB, a rare cosmic blast of gamma rays in which the engine powering the GRB stays active for longer. They are incredibly rare, with their cause still unknown.
"We don’t know what the central engine driving this outburst is, and that’s what makes this such a compelling event," Gompertz said. "The fact that we see a supernova tells us that a star has collapsed, which is the standard power source for GRBs, but it doesn’t immediately account for the extremely late flaring or unusually bright supernova. We can interpret that through previous events to some degree."