US-Led Team Claims 80% X-Ray Polarization Signal From Magnetar as QED Vacuum Effect Faces Challenge
Updated
Updated · physicsworld.com · Aug 17
US-Led Team Claims 80% X-Ray Polarization Signal From Magnetar as QED Vacuum Effect Faces Challenge
1 articles · Updated · physicsworld.com · Aug 17
Summary
Nature-published results from a US-led team say magnetar-pulsar 1E 1547.0−5408 offers the first direct glimpse of vacuum birefringence, a long-unconfirmed quantum electrodynamics prediction.
Up to 80% polarization at 2–3 keV emerged after combining IXPE and NICER X-ray data with Murriyang radio observations, letting researchers map the star’s magnetic geometry and separate plasma effects from vacuum effects.
The team argues the close alignment of X-ray and radio emission fits a vacuum polarized by the magnetar’s extreme field—up to 10^11 tesla—and is hard to explain with competing models.
Roberto Taverna’s Italy-led group disputes that conclusion, saying a small X-ray hotspot offset from the radio axis could still produce polarized radiation without invoking vacuum birefringence.
If confirmed, the finding would turn magnetars into natural laboratories for probing extreme-field quantum vacuum physics that cannot be reproduced in terrestrial experiments.
Could a tiny stellar hotspot shatter our best proof that empty space acts like a prism?
Will future telescopes finally prove empty space bends light or merely reveal an ordinary stellar surface?
Magnetar 1E 1547.0-5408 Shatters X-Ray Polarization Records: Testing Quantum Vacuum Birefringence in Space and on Earth
Overview
In 2025, astronomers used a combination of radio and X-ray telescopes to observe the magnetar 1E 1547.0-5408, capturing a record-breaking X-ray polarization nearly three times higher than seen in similar objects. This surprising result challenged standard models, leading scientists to simulate the magnetar’s geometry and discover its axes are nearly aligned, allowing Earth a direct pole-on view. This unique angle preserved the polarization signal, offering strong evidence for vacuum birefringence—a quantum effect predicted in 1936. To confirm these findings, researchers plan further multi-wavelength observations and advanced simulations, aiming to distinguish quantum effects from other astrophysical processes.