UC Berkeley Theory Confirmed as Astronomers Witness Birth of Magnetar Powering Superluminous Supernova

Astronomers detect a "chirp" in supernova SN 2024afav, confirming UC Berkeley's theory that spinning magnetars power the universe's brightest explosions.

By: AXL Media

Published: Mar 13, 2026, 7:37 AM EDT

Source: Information for this report was sourced from University of California - Berkeley

Validation of a Decade-Old Astrophysical Theory

Astronomers have achieved a milestone in stellar physics by capturing the birth of a magnetar—a neutron star with a magnetic field trillions of times stronger than Earth’s. This discovery, published in the journal Nature, confirms a hypothesis proposed in 2010 by UC Berkeley theoretical astrophysicist Dan Kasen. For years, the scientific community struggled to explain why "superluminous" supernovae remained bright for far longer than standard stellar explosions. The new data suggests that the intense energy of a rapidly spinning magnetar, hidden behind layers of debris, acts as a persistent engine that pumps luminosity into the expanding supernova cloud.

The Mechanics of the Relativistic Chirp

The definitive evidence came from a unique signal identified as a "chirp" in the light curve of supernova SN 2024afav. Analysis by graduate student Joseph Farah revealed that the supernova’s brightness did not fade smoothly but instead exhibited four distinct oscillations that increased in frequency over time. This pattern is explained by Lense-Thirring precession, a general relativity effect where a spinning mass drags the fabric of space-time along with it. As material from the explosion fell back toward the magnetar to form a misaligned accretion disk, the twisting of space-time caused the disk to wobble, creating a strobing effect that mirrored a bird’s chirp.

Calculating the Extremes of a Newborn Magnetar

By applying Einstein’s equations to the observed light fluctuations, the research team was able to calculate the physical properties of the newborn stellar remnant with high precision. The data indicates that the neutron star at the center of SN 2024afav is spinning at a rate of once every 4.2 milliseconds. Furthermore, its magnetic field is estimated to be 300 trillion times more powerful than the magnetic field of Earth. These extreme characteristics are the hallmarks of a magnetar and provide a clear distinction from standard pulsars, confirming that the most violent core collapses produce the most magnetic objects in the known universe.