In the galaxy NGC 3583, telescopes noticed a strange X-ray source: it flares up and then almost fades away. Breaking its light into a spectrum (a rainbow of energies), astronomers found a narrow dark dip — like a single note plucked from a chord.
This 'note' is created by protons trapped in a monstrous magnetic field. Like a string pressed on a fret, they vibrate at exactly one frequency. The pitch of the note revealed: the field is 400 trillion times stronger than Earth's. Before us is a neutron star with record magnetism — a magnetar.
A field of this strength not only tears atoms apart, stretching them into needles, but also turns the surrounding void into something like crystal, bending light rays.
A chunk of neutron star the size of a grain of sand weighs more than an aircraft carrier.