It is surrounded by a glowing, bubble-like nebula of particles flying away from the spinning star. The astronomers also measured the distance the nebula traveled since the supernova s initial explosion. With the pulsar s speed and distance, Gaensler and Frail calculated it was born at least 39,000 years ago. Other calculations indicated the position of the pulsar and the shapes of the nebula and supernova remnant are best explained if the pulsar is up to 170,000 years old. This is what Gaensler and Frail have done in order to get the age of a pulsar observed to be fleeing its parent supernova.
Pulsars live billions of years.
So we re suggesting it s a twenty-something instead of a teenager. We originally wanted to use a line about spinning spinsters, but that was judged politically incorrect. Seiradakis said the study might explain why many apparently young pulsars are not seen with supernova remnants. The pulsars may be so old the supernova shells would have dispersed. Frail and Gaensler said if other pulsars are older than they seem, astronomers may have to reconsider theories about how pulsars work, the fraction of supernovas that produce pulsars instead of black holes, and how supernovas explode asymmetrically to eject pulsars.