Overview
- A Nature paper published Monday reports combined IXPE and NICER X-ray polarimetry plus Murriyang radio polarization of magnetar 1E 1547.0−5408 that found X-ray polarization as high as about 80% at 2–3 keV.
- The team used radio polarimetry to infer the star’s magnetic and rotation geometry and linked the X-ray polarization direction to that geometry to argue the signal matches the predicted QED effect called vacuum birefringence.
- An independent analysis published in The Astrophysical Journal led by Roberto Taverna says the data can be reproduced by simpler astrophysical scenarios such as X-rays from a small hotspot or different viewing angles, so the observation is not yet a definitive detection.
- Vacuum birefringence is a 1930s quantum electrodynamics prediction that a very strong magnetic field makes empty space act like a prism by aligning virtual electron–positron pairs and changing how light is polarized.
- Researchers are planning more multiwavelength observations and more detailed QED-informed simulations to test the claim and to clarify whether the measured polarization is a true quantum signature or an effect of the magnetar’s emission geometry.