A spinning top that whirls so fast it completes 220 rotations in a single second: that's exactly what China's FAST radio telescope has caught. This is the pulsar PSR J1810-0623, a neutron star the size of a city but with more mass than the Sun. Every 4.55 milliseconds, its radio beam sweeps past Earth like a lighthouse in the cosmic ocean.
This pulsar is not alone. Orbiting it is a white dwarf — the cooled core of a former star, weighing about 0.64 solar masses. They complete a full orbit every 15.4 days, and the orbit is almost perfectly circular: its deviation from a perfect circle is less than the thickness of a hair at arm's length. Such precision suggests that the pulsar once actively siphoned matter from its companion, spinning faster and faster.
Astronomers monitored the system for six and a half years using FAST and the American Green Bank Telescope. They even measured the pulsar's weak magnetic field — a billion times weaker than that of typical neutron stars. The system moves leisurely, without large glitches, which is typical for such "recycled" pulsars in our Galaxy.
The pulsar spins 220 times per second — faster than the blades of a kitchen blender.