Pulsars are looking their age

New pulsar observations could lead to a drastic reappraisal of pulsar ages and evolution.

Pulsars, which "blink" regularly like powerful cosmic lighthouses in the depths of galaxies, are understood to be caused by beamed emission from rapidly spinning neutron stars, born in supernova explosions. If so, a pulsar would be expected to be accompanied by other remnants of the explosion.

As pulsars blast out tremendous amounts of energy, their observed pulse rate gradually slows down, and this "spindown" is used to determine the pulsar's age. However, one paradox is that these age estimates do not always tie in with the ages of their associated supernova remnants.

Now new observations by Gaensler (MIT) and Frail (US National Radio Astronomy Observatory) of the motion of Galactic pulsar B1757-24, relative to its physically associated supernova remnant, show that this pulsar, 15 000 light years away, is about 10 times as mature as would be expected simply from its observed spindown rate.