China's Five-hundred-meter Aperture Spherical Telescope (FAST) has identified a binary pulsar with an orbital period of 53.3 minutes, the shortest known period for a pulsar binary system. 

The research, led by a team of scientists from the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), was recently published in the journal Nature.

Pulsars, which are fast-spinning neutron stars, originate from the collapsed cores of massive dying stars through supernova explosions.

Observing pulsars is a crucial task for FAST, as it can help confirm the presence of gravitational radiation and black holes, as well as contribute to solving numerous other fundamental questions in physics.

The newly discovered binary pulsar, named PSR J1953+1844 (M71E), belongs to the spider pulsar system and possesses the largest orbiting angular velocity observed thus far. 

It represents the first instance of identifying the intermediate state of evolution from redback pulsars to black widow pulsars, bridging a gap in the spider pulsar evolution theory, according to Jiang Peng, chief engineer of the telescope.

Astronomical observations have revealed that certain pulsars have a companion star in a close orbit. "The orbital period of pulsars in evolution is quite short, and the distance between the two stars is very close, which poses a great challenge for observation," said Han Jinlin, researcher at NAOC. 

Fortunately, thanks to FAST's high sensitivity and detection capabilities, the evolutionary trajectory can be confirmed, Han added.

FAST is located in a naturally deep and circular karst depression in Pingtang County, Guizhou Province, in southwest China. The telescope became operational in January 2020 and officially opened to the world on March 31, 2021. It is widely regarded as the most sensitive radio telescope in the world.