International team uses China’s FAST telescope to shed light on spinning pulsar spider systems

“The two-star system is right in the middle of hundreds of millions of years of evolution. As the pulsar spins faster and faster, the feeding process – which draws them closer – stops,” said paper co-author Zhang Bing from the University of Nevada, Las Vegas.

“Next up, powerful particles generated by the pulsar are going to push the lighter and lighter companion star away and eventually erode it.”

The detection, made possible with the world’s largest and most sensitive radio telescope, filled an observation gap in the evolutionary theory of such binary systems, he said.

Scientists believe most stars are not isolated in the universe. More than half the single light points we see in the night sky are actually two or more stars orbiting together.

When the more massive star in a binary system goes supernova, it leaves behind a neutron star. The neutron star then evolves into a pulsar, spinning and giving off highly regular pulses of radiation that can rival the most precise atomic clocks on Earth.

If the supernova explosion is not violent enough to break the binary system, and the stars still stay relatively close, a spider system could form, according to Zhang.

So far, astronomers have observed two types of spider systems – redbacks and black widows – both named after spider species that notoriously eat their smaller partners.

While a redback pulsar has a relatively larger companion and they orbit around each other more slowly, a typical black widow pulsar has a companion no more than one tenth of the mass of the sun, and the two complete an orbit as rapidly as about an hour.