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.
