This artist's concept depicts a magnetar – a type of neutron star with a strong magnetic field – losing material into space in an ejection that would have caused the object's rotation to slow. Shown as thin green lines, the magnetic field lines influence the movement of charged material around the magnetar.

In October 2022, astronomers using NASA's NICER (Neutron Star Interior Composition Explorer) on the International Space Station and NuSTAR (Nuclear Spectroscopic Telescope Array) in low Earth orbit observed a rapid slowdown in a nearby magnetar called SGR 1935+2154. They believe the slowdown was caused by a rapid loss of material.

The slowdown coincided with the release a fast radio burst – an eruption of radio waves that last only for a fraction of a second but can release about as much energy as the Sun does in a year. The light also forms a laser-like beam, setting them apart from more chaotic cosmic explosions.

The telescopes were able to observe SGR 1935+2154 for hours, catching a glimpse of what happened on its surface and in its immediate surroundings both before and after the fast radio burst.

A Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory in Southern California for the agency's Science Mission Directorate in Washington, NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp. in Dulles, Virginia. NuSTAR's mission operations center is at the University of California, Berkeley, and the official data archive is at NASA's High Energy Astrophysics Science Archive Research Center at NASA's Goddard Space Flight Center. ASI provides the mission's ground station and a mirror data archive. Caltech manages JPL for NASA.

NICER, an Astrophysics Explorer Mission of Opportunity, is an external payload on the International Space Station. NICER is managed by and operated at NASA's Goddard Space Flight Center; its data is archived at NASA's HEASARC. NASA's Explorers program provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined, and efficient management approaches within the heliophysics and astrophysics science areas.