Astronomers trace mysterious 'fast radio bursts' to dead star

An artist's impression of SGR 1935+2154.
An artist's impression of SGR 1935+2154. Photo credit: European Space Agency

Scientists have traced a series of "fast radio bursts" to a dead star in our galaxy, in a find they say may solve a long-standing cosmic mystery.

Fast radio bursts are bright radio waves that pulse for just milliseconds before fading away, rarely to be seen again. They are so bright, in fact, they are billions of times more luminous than the sun.

Since they were discovered in 2007 scientists have been baffled by where they come from. But now they think they may have a clue to what causes the mysterious phenomenon.

Recently the space telescope Integral, operated by scientists at the European Space Agency (ESA), traced a fast radio burst to a highly magnetic dead star known as a magnetar, the agency said on its website this week.

Magnetars are stellar remnants with some of the most intense magnetic fields in the universe. They are a type of neutron star, the collapsed cores of some massive stars that pack roughly the mass of our sun into the size of a city.

The discovery was made after SGR 1935+2154, a magnetar discovered six years ago in the constellation of Vulpecula, became active again. Scientists noticed that not only X-rays were being radiated from the magnetar but also radio waves.

"We detected the magnetar’s burst of high-energy, or 'hard', X-rays using Integral on April 28," said Sandro Mereghetti of the National Institute for Astrophysics (INAF–IASF).

Observatories around the world were alerted to the discovery in seconds, said Mereghetti, "enabling the scientific community to act fast and explore this source in more detail".

Astronomers on the ground spotted the burst of radio waves using the CHIME radio telescope in Canada, an observation that was independently confirmed a few hours later by Survey for Transient Astronomical Radio Emission 2 in the US, ESA said.

"This is the first ever observational connection between magnetars and fast radio bursts.

"It truly is a major discovery, and helps to bring the origin of these mysterious phenomena into focus."