Astrophysicists Create the First-Ever Surface Map of a Pulsar Using Data from NASA’s NICER Telescope on the ISS
Scientists using data from NASA's NICER telescope onboard the ISS have created the first-ever surface map of a pulsar, according to reports from Space.Com.
"Thanks to NICER's detailed data, open-source tools, high-performance computers and great teamwork, we now have a framework for developing more realistic models of these objects," said Thomas Riley, a doctoral student in computational astrophysics who led one of the research teams.
A pulsar is a type of neutron star that emits bursts – or pulses – of radiation. At the same time, the pulsar itself is spinning like a top. These stars also have strong magnetic fields channel jets of superaccelerated radioactive particles through the stars' north and south poles, which creates the bursts of light we use to find them. They are a sort of radio wave strobe light, if you will. These pulses don't last very long: a couple of seconds, max – and sometimes the magnetic field doesn't line up with the rotational axis, so we can't always see this light. According to NASA, another way to think about pulsars is like a lighthouse beam: you can only see the light when it is pointing directly at you.
The NICER telescope (Neutron star Interior Composition Explorer) was installed on the ISS in June 2017 to monitor and collect data on neutron stars. Incredibly, it is also being used to test pulsars as potential navigation beacons for deep space missions. NASA astronomers were studying pulsar J0030+0451 in the constellation Pisces about 1,100 light-years away. From the NICER data, scientists were able to map the star's size and shape while mapping the shape and location of million-degree "hot spots" on the star's surface.
Neutron stars are the densest visible structure in our universe. They are the white-hot core that remains after a star one to three times the mass of our sun collapses on itself with enough force to crush most protons and electrons into neutrons. Larger stars will collapse into a black hole – that's how dense neutron stars are. They're the equivalent of compressing 500,000 planet Earths into an area roughly the size of Manhattan. The only thing denser than a neutron star (that we know of) is the uncharted abyss of a black hole.
Paul Hertz, the astrophysics division director at the NASA Headquarters in Washington, said, "From its perch on the space station, NICER is revolutionizing our understanding of pulsars…Pulsars were discovered more than 50 years ago as beacons of stars that have collapsed into dense cores, behaving unlike anything we see on Earth. With NICER we can probe the nature of these dense remnants in ways that seemed impossible until now."
You can read a collection of papers on this study that have been published online in The Astrophysical Journal Letters, and see the map in NASA Goddard's video below!