[Music throughout] NASA’s NICER X-ray telescope on the International
Space Station has just shown that random outbursts from pulsars
pack more of a punch than previously thought. Pulsars are
rapidly spinning neutron stars, the crushed cores of exploded
stars. One of the best-known pulsars lies at the heart of the
famous Crab Nebula, located about
6,500 light-years away. Light from the supernova that formed it reached
Earth less than a thousand years ago, in the year 1054.
The Crab pulsar spins 30 times a second and steadily
blinks in radio, visible light, X-rays and gamma rays.
But it also emits random, jumbo bursts called
giant radio pulses that can be more than 10 times stronger than its regular
signals. Now, thanks to NICER’s sensitivity,
astronomers have shown that each giant pulse comes with an increase in
X-ray brightness as well. Observing the Crab simultaneously with
NICER and radio telescopes in Japan, astronomers captured
data over some 3.7 million rotations. They show
a nearly 4% increase in X-ray emission with each giant
pulse. This means the phenomena responsible for giant radio
pulses produce 10 or more times the energy previously
estimated from radio and visible data alone. Astronomers
think all these signals originate from particle interactions in the pulsar’s
rapidly spinning magnetic field, but the details remain poorly known.
Better understanding of giant pulses
may help scientists figure out how pulsars like the Crab do what they do.
It may also provide us with insight into a much more powerful
phenomenon called Fast Radio Bursts, which are linked to spinning
neutron stars in our galaxy, and others much farther away.
[NASA]