As neutron stars age, they lose angular momentum and slow down, and their magnetic fields weaken. Not all magnetars blast out radio waves or spin rapidly. It’s little wonder neutron stars and magnetars are considered exotic.

All of this is wrapped up in the most powerful magnetic fields in the universe, 10 trillion times more powerful than the magnetosphere of Earth. The rapid diameter reduction causes the newly born neutron star to increase its rate of rotation, leading to it spinning as fast as 700 times a second. This results in a stellar remnant with matter so dense that, if a tablespoon of it were brought to Earth, it would weigh an incredible 1 billion tons. The collapse causes a stellar core with a mass around that of the sun to crush down to a width no greater than the diameter of around 12 miles (19 kilometers) - about the size of a city on Earth. This results in their core collapsing and the outer layers of these stars being shed in massive supernova explosions. As they exhaust the fuel for nuclear fusion, the stars can no longer balance themselves against the inward force of their own gravity. Like all neutron stars, magnetars like GPM J1839-10 are created when massive stars reach the end of their lives.

Existence below the deathline makes these neutron stars even more extreme

Dead space story is stupid