What are pulsars and their information.

 Pulsars belong to a family of object called neutron stars that form when a star more massive than a sun run out of the fuel in it's core and collapsed in on itself. The neutron star is a dense nugget of material left over after this explosive death.

The only object with a higher density then a neutron star is a black hole, which is also forms when a dying star collapse. The most massive neutron star ever measured is 2.04 times the mass of hen.

From Earth the pulsars often look like flickring on and off, on and off, they seem to link with a regular Rythem. But the light form pulsars does not actually flicker or pulse.