Neutron stars were discovered over thirty years ago by Jocelyn Bell. Here, she describes some of the characteristics of these objects. Actually, the first neutron star was first identified in the Crab Nebula because of its regular pulses of radio energy. This behavior was somewhat unexpected, and the radio source was first thought to be artificial. One of the first pulsars studied was the Vela pulsar. The constellation of Vela is in the southern sky, so many of you northern hemisphere types have probably never heard of it. Listen to this recording of the Vela pulsar. Not all pulsars emit at radio frequencies. We now have evidence of X-Ray pulsars, which are made to spin as fast as one thousand times per second by accreting material from a companion star. In orbit around the Earth right now is the Chandra X-Ray observatory. The scientists at that facility present a wealth of information about neutron stars on their website. So what, exactly, is going on inside a neutron star? Here’s one possible description. If the original star is massive enough, the ultimate end in that case would be a black hole.