Magnetar Polarizes X-rays Up to 47%
Neutron stars are ultra-dense remnants of supernovae the size of a city. In the 1930s, Fritz Zwicky hypothesized their existence, and later Jocelyn Bell Burnell discovered pulsars — rapidly rotating neutron stars.
A Black Hole's X-ray Compass
The black hole GS 1354-64 in the constellation Musca woke up in 2025 and began greedily pulling matter from its companion star. The orbiting X-ray telescope IXPE caught it at a rare moment: the outburst had already subsided, but the system had not yet settled down.