Crab Nebula

The Crab Nebula, also known as M1, is a cloud in the Perseus Arm of the Milky Way Galaxy. It is the remnant of a recent supernova and currently measures 11 light years across.

M1 produces a "visual" pulsar effect. About once every five minutes, changes occuring in the central neutron star's pulsation affect the amount of polarization, causing the light waves to sweep around like a giant cosmic lighthouse.