Magnetised dead star likely has solid surface

artist's impression of a magnetar - A signature in the X-ray light emitted by a highly magnetised dead star known as a magnetar suggests the star has a solid surface with no atmosphere, according to a new study by an international collaboration co-led by UCL researchers. The study, published in the journal Science , uses data from a NASA satellite, the Imaging X-ray Polarimetry Explorer (IXPE), which was launched last December. The satellite, a collaboration between NASA and the Italian Space Agency, provides a new way of looking at X-ray light in space by measuring its polarisation - the direction of the light waves' wiggle. The team looked at IXPE's observation of magnetar 4U 0142+61, located in the Cassiopeia constellation, about 13,000 light years away from Earth. This was the first time polarised X-ray light from a magnetar had been observed. Magnetars are neutron stars - very dense remnant cores of massive stars that have exploded as supernovae at the ends of their lives. Unlike other neutron stars, they have an immense magnetic field - the most powerful in the universe.