The Crab Nebula and the pulsar at its center are endlessly fascinating. The pulsar is a neutron star, with the same mass as our Sun but only the size of a city. It rotates 30 times per second, flashing like a lighthouse as it does so. It is very nearly, but not quite, an ideal clock, without any outside influence to disturb it. At Jodrell Bank Observatory, astronomers have been watching the pulsar for over 40 years, timing it without missing a beat while it rotated more than 30 billion times. Putting together the results from our radio observations with data from the opposite end of the electromagnetic spectrum has proved remarkably rewarding.
Via Dr. Stefan Gruenwald