 Pulsars are just a kind of neutron stars so it’s essential to get a grip of these first.  The stars that come into being at the end of a massive star’s lifetime are called neutron stars.  When these massive stars have finished burning their nuclear fuel, they undergo a supernova explosion.  The event of formation of neutron stars is called core-collapse supernova’.  The central region of the star collapses so much that even electron, proton combine to form neutron and hence the name neutron star.

+  Small diameter + High mass=Super High Density.  Density of an average neutron star would be around 5 x kg/m 3.  Rotates about 40,000 times a minute.  Crust is about 1 km thick but 100 billion times stronger than steel.  Has a very tiny atmosphere(made mostly of iron 56 and lighter elements).  The surface is about 1 million degrees Celsius.  They have an escape velocity of about 33% the speed of light.

 Discovered by Jocelyn Bell in  She observed a pulsar whose pulsations lasted for about 0.04 seconds and were seconds apart, called pulsar period.  It was initially named LGM-1, for Little Green Men.  Bell and her instructor assumed it as a sign of extraterrestrial life.  Later Thomas Gold recognized that pulsars were rotating neutron stars.  So pulsar is a kind of neutron star that emits beams of radiation that sweep through Earth’s line of sight.  A special phenomenon called lighthouse effect is observed.  All pulsars are neutron stars, not all neutron stars are pulsars!

WWhen normal stars collapse into pulsars(neutron stars) their magnetic fields also compress and become enormously intense as much as a trillion times Earth’s magnetic field. PPulsars spin fast for the same reason ice skaters pull in their arms to spin, following conservation of angular momentum.

IIn Map reading. AAs precise clocks. AAs gravitational wave detectors. Relative position of the Sun to the centre of the galaxy and 14 pulsars

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