Astronomers discover neutron star spinning at record-breaking 716 times per second

Astronomers have identified one of the fastest-spinning neutron stars in the universe, located in the binary system 4U 1820-30, which rotates at an astonishing 716 times per second. This discovery was made using NASA's Neutron Star Interior Composition Explorer (NICER) telescope, mounted on the International Space Station.

The neutron star, about 26,000 light-years from Earth in the Sagittarius constellation, shares the binary system with a white dwarf that orbits it every 11 minutes, setting a record for the shortest orbital period observed in such systems. "We were studying thermonuclear explosions from this system and found remarkable oscillations, suggesting a neutron star spinning around its center axis at an astounding 716 times per second," said Gaurava K. Jaisawal of Denmark based space research institute DTU Space.

The team’s research, which monitored X-ray bursts from the system between 2017 and 2021, revealed 15 thermonuclear explosions. One of these explosions confirmed the spin rate through "thermonuclear burst oscillations," aligning precisely with the star's rotation speed.

In dense environments like those of neutron stars, matter accumulates on the star’s surface and occasionally erupts in powerful thermonuclear explosions. These events make the neutron star appear 100,000 times brighter than the sun. "By studying these extreme bursts, we gain new insights into binary star systems and the formation of elements in the universe," said DTU Space scientist Jerome Chenevez.