Berkeley astronomers capture first sight of a magnetar’s birth in superluminous supernova SN 2024afav — and hear a “general relativity chirp”
Berkeley astronomers directly observed the birth of a magnetar inside superluminous supernova SN 2024afav and detected a general-relativity “chirp” in its light curve, providing direct evidence that magnetars power some of the universe’s brightest explosions.
- Event: SN 2024afav erupted in December 2024 and displayed short, repeated brightening “bumps” interpreted as a general relativity chirp (UC Berkeley press release; Life Sciences Berkeley).
- Magnetar properties: The newborn magnetar’s initial spin is estimated at ~4.2 milliseconds with a magnetic field ≈10^15 gauss — roughly 300 trillion times Earth’s field.
- Theory confirmed: Observation corroborates the 2010 magnetar-powered Type I superluminous supernova model (Dan Kasen; Lars Bildsten; Woosley) and appears in Nature (published March 11, 2026).
- Team: Lead author Joseph Farah (UCSB/Las Cumbres Observatory) with collaborators including Alex Filippenko and D. Andrew Howell; funding and institutional support from UC Berkeley donors and partners.
How astronomers “heard” a magnetar
SN 2024afav stood out for two measurable features: exceptional luminosity and a sequence of short, repeated brightening “bumps” in its light curve. Detailed photometry and modeling show those bumps form a predictable chirp produced by the newborn magnetar’s extreme gravity and rapid spin.
According to the research, general relativity effects — including gravitational redshift and photon trapping close to the compact object — modulate how rotational energy transfers from the magnetar into the expanding supernova ejecta. The result is a pattern of brief brightening events as the magnetar slows and deposits energy, creating a signature that matches relativistic calculations.
The magnetar model and why it matters
In 2010, Dan Kasen and collaborators proposed that some Type I superluminous supernovae (SLSNe-I) are sustained not only by the explosion itself but by a compact, rapidly rotating neutron star with an enormous magnetic field — a magnetar. When a massive star’s core collapses into a ~10-mile-wide neutron star that spins hundreds to thousands of times per second and carries a ~10^15 gauss field, that star can inject energy into the debris and keep the supernova extraordinarily bright for extended periods.
This new observation of SN 2024afav supplies direct empirical support for that mechanism and provides a measurable template to search for other magnetar-powered transients in survey data.
What the team observed and measured
The transient was tracked by a distributed network of telescopes, including data from Las Cumbres Observatory and extensive follow-up spectroscopy and photometry. Light-curve modeling yields the best-fit magnetar parameters:
- Initial spin: ~4.2 milliseconds.
- Magnetic field: on the order of 10^15 gauss (≈300 trillion times Earth’s magnetic field).
- Signature: Repeated short brightening events — the general relativity chirp — consistent with relativistic photon transport near the compact object.
The modeling combines observed late-time brightness and the timing/amplitude of the bumps; inclusion of general relativistic effects near the magnetar produced the best agreement with data.
Voices from the research team
“To see a clear effect of Einstein’s general theory of relativity is always exciting, but seeing it for the first time in a supernova is especially rewarding,” said Alex Filippenko, UC Berkeley astronomy professor.
“This is the most exciting thing I have ever had the privilege to be a part of… It’s the universe telling us out loud and in our face that we don’t fully understand it yet, and challenging us to explain it,” said graduate student Joseph Farah, lead author.
“I think Joseph has found the smoking gun… It is incredibly elegant,” said D. Andrew Howell (Las Cumbres Observatory / UCSB).
Team, funding and collaboration
The research team draws on expertise at UC Berkeley, UC Santa Barbara, Las Cumbres Observatory, the Flatiron Institute and other institutions. Joseph Farah (lead author) is affiliated with UCSB and Las Cumbres and will join UC Berkeley as a Miller Postdoctoral Fellow in Dan Kasen’s group. Funding for parts of the work included UC Berkeley donors and institutional grants, highlighting public–private collaboration across telescope networks and university teams.
Why this advances astrophysics
SLSNe have challenged astrophysicists since their discovery in the early 2000s because they are far brighter and longer-lived than typical core-collapse events. The magnetar explanation, proposed in 2010, has been debated; SN 2024afav provides direct observational evidence that magnetars can power these explosions. Moreover, the clear general relativity chirp offers a new, measurable probe of compact-object physics that can be hunted in future surveys to refine formation models and frequencies of magnetar versus black-hole outcomes.
Next steps: hunting more chirps
The team recommends using the SN 2024afav signature as a template to search archived and incoming survey light curves for similar chirps. A larger sample will enable tests of magnetar formation pathways, the fraction of massive-star deaths that produce magnetars rather than black holes, and possible links to other phenomena such as fast radio bursts.
Implications for Huntington Beach, California
Economic impact: Huntington Beach-based technology firms and observatory suppliers could benefit from regional ties to astrophysics research. UC campuses and spin-offs often partner with private industry on sensors, software and data management, potentially supporting local jobs in engineering, data science and optics.
Political consequences: For conservative readers, the discovery exemplifies public investment in basic science producing high-profile results and local economic returns via grants and donor funding, illustrating the value of public–private research models.
Social and cultural effects: Local schools and community colleges can leverage the discovery to boost STEM engagement; outreach programs, planetariums and museums may see increased attendance. The finding reinforces Southern California’s identity as a hub of innovation and technical skill.
Practical opportunities: While not changing daily life, the discovery provides content for education and outreach, and potential contracting opportunities for local optics, software and data-service businesses supporting telescope projects and follow-up instrumentation.
Sources and further reading
- UC Berkeley news release
- Life Sciences Berkeley summary
- Smithsonian Magazine summary
- National Today brief
- ScienceSPrings copy of UC release
- Perplexity summary
Reporting based on the Nature paper published March 11, 2026, and institutional releases from UC Berkeley and partners.
