Context

Astronomers have recently reported a fast radio burst (FRB) whose characteristics are different from almost all other FRBs previously detected, except one.

About

Fast radio burst (FRB):

• FRBs are bright flashes of light that appear for a few milliseconds and then vanish.
• The phenomenon was discovered in 2007, by graduate student David Narkevic and his supervisor Duncan Lorimer.
• The source of these highly energetic events is a mystery, but clues as to their nature are being gradually collected.
• Since 2007, 140 more were discovered until June 2021. Their origins are unknown, and their appearance is unpredictable.

Fast radio burst 20190520B:

• The new source, Fast radio burst 20190520B, was detected with the Five hundred-meter Aperture Spherical radio Telescope (FAST) in Guizhou, China in May 2019.
• It emits frequent, repeating bursts of radio waves. And between bursts, it constantly emits weaker radio waves.
• Only one FRB has been previously observed to behave this way. Called FRB 121102, which was discovered in 2012.
  

How a Burst Bursts

• Astronomers have racked up roughly 50 separate theories to explain fast radio bursts — a tally that until recently outnumbered the events.
• The ideas include a variety of wild scenarios involving evaporating black holes, snapping cosmic strings, and even the propulsion systems of alien civilizations.
  

What is a magnetar?

• A magnetar is a neutron star, “the crushed, city-size remains of a star many times more massive than our Sun.”
• The magnetic field of such a star is very powerful, which can be over 10 trillion times stronger than a refrigerator magnet and up to a thousand times stronger than typical neutron stars.
• Neutron stars are formed when the core of a massive star undergoes gravitational collapse when it reaches the end of its life.