The magnetar in question,
4U 0142+61, is located some 13,000 light-years from Earth in the
Cassiopeia constellation. Magnetars are a type of neutron star — a collapsed supergiant star —named because they have extremely
powerful magnetic fields.
Surprisingly, the polarized X-ray data revealed that magnetar 4U 0142+61 doesn't have an atmosphere, as the scientists on the project had expected. Most strikingly, the polarization angle at higher energies was flipped 90 degrees when compared with light from lower energies.
This indicates that the magnetar has a solid surface surrounded by a magnetic field. According to scientists, the "solid crust of the star is thought to be composed of a lattice of ions, held together by the magnetic field. The atoms would not be spherical but elongated in the direction of the magnetic field."
interestingengineering.com
