What causes mysterious radio wave bursts from deep space? Astronomers may be one step closer to providing a single answer to this question. Two NASA X-ray telescopes recently observed such an event, known as a fast radio burst, just minutes before and after the event. This unprecedented insight puts scientists on the path to better understanding these extreme radio frequencies.

Although they last a fraction of a second, fast radio bursts can release approximately as much energy as the Sun produces in a year. Their light also creates a laser beam, distinguishing them from more chaotic cosmic explosions.

Because the bursts are so short, it is often difficult to detect exactly where they are coming from. By 2020, those whose origins were traced were coming from outside our galaxy; They were too far away for astronomers to see what created them. Then, a fast radio burst erupted in Earth’s home galaxy, originating from an extremely dense object called a magnetar (the shattered remains of an exploded star).

In October 2022, the same magnetar, designated SGR 1935+2154, produced another fast radio burst, which was studied in low detail by NASA’s NICER (Neutron Star Interior Composition Explorer) and NuSTAR (Nuclear Spectroscopic Telescope Array) on the International Space Station. Earth’s orbit.

Telescopes monitored the magnetar for hours, giving a glimpse of what was happening on the source object’s surface and in its immediate surroundings before and after the fast radio burst. The results are described in a new study published in the journal. NatureIt is an example of how NASA telescopes can work together to observe and track ephemeral events in space.

The explosion occurred between two “glitches” when the magnetar suddenly began spinning faster. SGR 1935+2154 was estimated to be about 12 miles (20 kilometers) in diameter and rotated about 3.2 times per second; This meant that its surface was moving at approximately 11,000 km/h. Decelerating or accelerating requires significant energy.

So the study authors were surprised to find that between failures, the magnetar slowed to a speed lower than the speed before the failure in just nine hours, nearly 100 times faster than anything ever seen in a magnetar.

“Usually when malfunctions occur, it takes weeks or months for the magnetar to return to its normal speed,” said Chin-Ping Hu, an astrophysicist at the National Changhua University of Education in Taiwan and lead author of the new study. “It’s clear that much shorter timescales occur in these objects than we previously thought, and this may be due to how quickly radio bursts are generated.”

Scientists have to take many variables into account when trying to understand exactly how magnetars create fast radio emissions.

For example, magnetars (a type of neutron star) are so dense that a teaspoon of their material weighs about a billion tons on Earth. Such a high density also means a strong gravitational force: A marshmallow falling on a typical neutron star would hit with the force of an early atomic bomb.

The strong gravity means that the magnetar surface is a volatile place that regularly emits high-energy X-rays and bursts of light. Before the fast radio burst in 2022, the magnetar began emitting X-rays and gamma rays (even more energetic wavelengths of light), which are observed in the peripheral light of high-energy space telescopes. This increase in activity caused mission operators to aim NICER and NuSTAR directly at the magnetar.

“All the X-ray bursts that occurred before this failure, in principle, had sufficient energy to produce a fast radio burst, but they did not,” said study co-author and researcher Zoravar Wadiasingh from the University of Michigan. Maryland, College Park and NASA’s Goddard Space Flight Center. “It seems like something changed during the slowdown and the right conditions were created.”

What else could have happened to SGR 1935+2154 to create a fast radio burst? One reason for this could be that the magnetar’s exterior is solid, and the high density compresses its interior into a state called superfluidity. At times, they can be out of sync, like water churning around in a spinning aquarium. When this happens, the fluid can deliver energy to the cortex. The authors of the paper believe this likely caused both failures leading to fast radio bursts.

If the initial failure caused a crack in the magnetar’s surface, it could eject material from the star’s interior into space, like a volcanic eruption. Since mass loss causes spinning objects to slow down, researchers believe this could explain the magnetar’s rapid deceleration.

But by observing only one of these events in real time, the team still cannot say for sure which of these factors (or others, such as the magnetar’s strong magnetic field) could have caused the fast radio burst. Some may not be attached to the package at all.

“We have clearly observed something important for our understanding of fast radio bursts,” said George Younes, a Goddard researcher and member of NICER’s research group specializing in magnetars. “But I think we need a lot more data to solve the mystery.”