As winter sets in around North America, it seems the countryside isn’t the only place cooling off. Astronomers with NASA’s Chandra X-ray Observatory have found a pulsating star only 10,000 light years from Earth that’s feeling the chill too. The object discovered by the astronomers is a type of whirling neutron star known as a pulsar. The remnant of a once bright and burning star, a pulsar spins and flashes radiation like a lighthouse on a distant point. Understanding how pulsars function could help explain how nuclear forces and magnetism work in our universe.
From NASA:
A Chilling Discovery on Pulsating Star
As winter sets in around North America, it seems the countryside isn’t the only place cooling off. Astronomers with NASA’s Chandra X-ray Observatory have found a pulsating star only 10,000 light years from Earth that’s feeling the chill too.
The object discovered by the astronomers is a type of whirling neutron star known as a pulsar. The remnant of a once bright and burning star, a pulsar spins and flashes radiation like a lighthouse on a distant point. Understanding how pulsars function could help explain how nuclear forces and magnetism work in our universe.
First identified by Asian astronomers in the year 1181, pulsar 3C58 should have a temperature of about 1.5 million degrees Celsius. However, puzzled scientists have found the star’s temperature to be far below that.
”We now have strong evidence that, in slightly more than 800 years, the surface of the 3C58 pulsar has cooled to a temperature of slightly less than a million degrees Celsius,” said Patrick Slane of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. ”A million degrees may sound pretty hot, but for a young neutron star, that’s like the frozen tundra in Green Bay, Wisc.”
Neutron and pulsar stars are what astronomers believe are left after a regular star collapses in a supernova explosion. When the star implodes, electrons and protons in its core violently smash into one another, destroying themselves to form neutrons and tinier neutrinos. A powerful shockwave then blasts away the star’s outer material, leaving only a concentrated core of neutrons behind.
Once the new star is formed, high-speed collisions between neutrons and other particles inside the core create even more neutrinos. The neutrinos interact weakly with the neutrons, causing them to easily escape the star and take heat energy with them. If the number of departing neutrinos climbs, so will the cooling rate of the star. The fact that 3C58’s temperature plummeted so quickly leads astronomers to believe its core is abuzz with neutrino activity.
Researchers wonder if the pulsar’s rapid cooling is triggered by something new in the mix of particles inside the core. One idea is that a higher number of protons survived the supernova explosion, or perhaps the core is infested with small specks of matter known as pion condensates.
Aside from the star’s swift change in temperature, scientists also detected loops of magnetic energy surrounding the pulsar. Jets of high-energy particles can also be seen shooting out of the pulsar. Evidence from these and similar discoveries suggests that pulsars with defined magnetic fields are powerful generators of high-energy particles.
Why pulsar 3C58 has cooled off so quickly remains a mystery. Determining the cause could reveal valuable details about the fundamental ways matter and energy interact in the universe. One thing’s for sure: the research is just heating up.
