|Image Credit: Swinburne Astronomy Productions, Swinburne University of Technology|
First, let's go over what the astronomers observed. The team, headed by Professor Matthew Bailes of Swinburne University of Technology in Australia, was looking at a millisecond pulsar. Pulsar are the remains of very massive stars that exploded as supernovae at the end of the stars' lives. Pulsars typically contain about 1.3 times the mass of our sun squeezed into a sphere only a dozen miles across. This is so dense that ordinary atoms cannot exist, and most of the protons and electrons that made up the atoms in the original star merge to form neutrons. We therefore call these very dense remains of massive stars neutron stars.