Over 1,000 pulsars: China's FAST telescope leads the world in pulsar discovery

China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest single-dish and most sensitive radio telescope, has identified more than 1,000 new pulsars since its launch in 2016, said its operator, the National Astronomical Observatories under the Chinese Academy of Sciences (NAOC), on Tuesday.

FAST's discovery of new pulsars has surpassed the total number of pulsars found by all other international telescopes combined, according to the NAOC.

What are pulsars?

Pulsars are rapidly rotating neutron stars that originate from the collapsed cores of massive dying stars through supernova explosions. They are known for emitting electromagnetic pulse signals.

Han Jinlin, a researcher at the NAOC, explained that each pulsar has a unique pulse and rotation frequency, making them somewhat like a lighthouse in the universe.

"Among the pulsars discovered by our team, some have special radiation characteristics, which only emit pulses occasionally, one every few minutes," Han told China Media Group. "These previously unknown pulsars are highly significant. Pulsar radiation has been a puzzle for half a century, and FAST's highly sensitive observations provide new clues to help solve this mystery."

Han also noted the potential use of pulsars in future interstellar navigation, saying pulsars could serve as a navigational system if humans can travel to other planets. "By accurately measuring their coordinates and tracking the phase positions of their signals, we could prevent getting lost during interstellar journeys," he explained.

Impressive performance of FAST

In just about seven years, FAST has detected over 1,000 pulsars, including many binary and millisecond pulsars. This has not only expanded the variety and number of pulsars studied but also contributed significantly to human's understanding of their formation and evolution.

The construction of FAST started in March 2011, located in a naturally deep and round karst depression in southwest China's Guizhou Province. It went into formal operation in January 2020 after a debugging process and became open to the global scientific community in March 2021.

With pulsar observation an important task, FAST has also made a number of important original achievements in the study of fast radio bursts, neutral hydrogen and nanohertz gravitational waves. Notably, it discovered a pulsar binary system with the shortest known orbital period and provided key evidence for the existence of nanohertz gravitational waves.

Within just a few years, China has been in the forefront of pulsar discovery, which has significant implications for testing cutting-edge physical theories, such as Albert Einstein's theory of general relativity, said Jiang Peng, director of FAST Operation and Development Center.

"China is making its own contributions to advancing humanity's understanding of the mysteries of space," said Jiang.

In the future, FAST will further enhance its sensitivity and spatial resolution by adding auxiliary antennas. This upgrade will enable a leap in its capability, helping to discover more low-luminosity and distant pulsars. A systematic pulsar search is expected to increase the likelihood of discovering rare celestial objects.