World's largest telescope finds new pulsars

An illustration shows how FAST receives radio waves emitted by distant pulsars, the rapidly rotating cores of dead stars. At left, a photo shows the huge telescope in Guizhou province. PROVIDED TO CHINA DAILY

Chinese researchers have discovered six pulsars, which are superheavy remnants of massive stars, using its Five-hundred-meter Aperture Spherical Radio Telescope, known as FAST.

It is the first time Chinese scientists have discovered pulsars using the world's largest single-dish radio telescope, thus opening a "new era of Chinese original space discovery", Yan Yun, director of the National Astronomical Observatories of China, said on Tuesday.

The first two pulsars, named J1859-01 and J1931-01, were discovered in August and were confirmed in September by the 64-meter radio telescope at Parkes Observatory in Australia.

J1859-01 is 16,000 light years from Earth and rotates once every 1.83 seconds, while J1931-01 is 4,100 light years away and rotates once every 0.59 seconds, according to scientists.

Since its completion in September 2016, FAST has discovered two dozen highly possible candidates for pulsars, said Li Di, the telescope's deputy chief engineer.

Last week, FAST also confirmed four new pulsars, but their details are still being analyzed.

"Pulsars are superdense cores of massive stars that went supernova and died, hence they have incredible mass, extremely strong magnetic fields, and they spin like a clock and shoot out strong beams of electromagnetic radiation," Li said.

"The conditions on a pulsar are far more extreme than any lab simulation on Earth. Examining them and seeing how they interact with other stars can help us tackle major scientific issues, such as the origin and evolution of the universe, finding gravitational waves and navigating spacecraft."

Li said FAST is set to be fully operational by the end of 2019. In the meantime, scientists there will continue to test FAST and cooperate with foreign scientists on space exploration.

Located in a natural depression in Guizhou province, FAST consists of 4,600 triangular panels that form a receiving dish about the size of 30 soccer fields.

Apart from its massive size, it also has unmatched accuracy and sensitivity, allowing scientists to find previously hidden stars, Li said. "When we first received the pulsar signals, you can hear their frequency signals beep like the beating of a baby's heart," he said.

Moreover, FAST is capable of surveying the night sky for multiple scientific data at once, ranging from galaxy structure to star explosions, while other telescopes can only manage one task at a time, he added.

George Hobbs, a research scientist from the Commonwealth Scientific and Industrial Research Organization in Australia, said, "The world's most exciting radio astronomy projects are happening in China with FAST, and it is a great honor for the Australian science community to be part of the process."

Hobbs was also the leading scientist for the Parkes Pulsar Timing Array project, the telescope that confirmed China's pulsar findings. Since the discovery of pulsars in 1967, scientists have found more than 2,700 of them, more than half of which were found by Parkes Observatory, Hobbs said.

"Australia is the world leader in finding pulsars, but China will catch up really fast with FAST's help," he said. "If FAST can find a binary system in which a pulsar is orbiting a black hole, this will be a discovery worthy of a Nobel Prize."