In the depths of our Galaxy, astronomers found an unusual pulsar — a source of radio bursts that repeat every 76 seconds. Ordinary pulsars are fast-spinning neutron stars, remnants of supernova (explosions of massive stars) left behind as city-sized objects; the very concept of a neutron star was predicted by Fritz Zwicky. But this one spins suspiciously slowly. Scientists guessed it might be a white dwarf — another type of stellar remnant, predicted by Subrahmanyan Chandrasekhar. A white dwarf, like a heavy flywheel, could store enough rotational energy to power radio bursts even at a slow spin.

To test the idea, the Chandra space telescope was pointed at the object. X-rays should arise if a spinning magnetic field rips from the star's surface a stream of antimatter — lightweight twin particles of ordinary electrons. They accelerate almost to the speed of light and glow in X-rays. But precise spectroscopy (the study of light by its colors) detected not a single photon. If it were a white dwarf, the radiation would have been tens of times brighter — the telescope would certainly have seen it. So, the white dwarf is ruled out. For a neutron star, the estimated rotational power is low, but no traces of it are visible either.

So what then powers this radio beacon? Most likely, a gigantic magnetic field of a neutron star — a hundred trillion times stronger than Earth's. It's like a bicycle light where the light comes not from spinning a dynamo but from shaking a magnet: the neutron star's magnetic field twists and reconnects, blasting out energy without fast rotation. Such a powerful field can even influence time dilation near the star. This discovery also ties to gravitational waves — ripples in space that such objects can generate. It reminds us that alongside black holes there are other, no less amazing, inhabitants of the Universe.