Astrophysical fluid dynamics she pulls in her arms. These stars gradually slow down over the eons, but those bodies that are still spinning rapidly may emit radiation that from Earth appears to blink on and off as the star spins, like the beam of light from a turning lighthouse. This "pulsing" appearance gives some neutron stars the name pulsars. After spinning for several million years pulsars are drained of their energy and become normal neutron stars. Few of the known existing neutron stars are pulsars. Only about 1,000 pulsars are known to exist, though there may be hundreds of millions of old neutron
Neutron star explanation does not fully explain magnetic field strengths of neutron stars. The gravitational field at a neutron star's surface is about times stronger than on Earth, at around . Such a strong gravitational field acts as a gravitational lens and bends the radiation emitted by the neutron star such that parts of the normally invisible rear surface become visible. If the radius of the neutron star is 3"GM"/"c" or less, then the photons may be trapped in an orbit, thus making the whole surface of that neutron star visible "from a single vantage point", along with destabilizing photon orbits at