Magnetic field reversal in the turbulent environment around a repeating fast radio burst

Understand

Fast radio bursts (FRBs) are brief, intense flashes of radio waves from unidentified extragalactic sources.

• Polarized FRBs originate in highly magnetized environments.
• We report observations of the repeating FRB 20190520B spanning seventeen months , which show its amount of Faraday rotation is highly variable and twice changes its sign.
• The FRB also depolarizes below radio frequencies around 1 to 3 GHz.