Actually, the group of bananas commonly referred to as a bunch at the store is actually a hand, or less commonly tier.
PSR B1509-58 - X-rays from Chandra are gold; Infrared from WISE in red, green and blue/max. A pulsar (from pulse and -ar as in quasar) is a highly magnetized, rotating neutron star or white dwarf, that emits a beam of electromagnetic radiation. This radiation can be observed only when the beam of emission is pointing toward Earth (much like the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission.
We start by describing how astronomers discover and subsequently observe pulsars. We continue with a section on the theory of pulsars where we explain why pulsars are thought to be neutron stars (the collapsed core of a star that underwent a supernova explosion).