716 rotations per second: Astronomers find one of the fastest spinning stars in the Universe

An international team of researchers has reported the discovery of one of the fastest spinning neutron stars. It rotates at a speed of 716 times per second. 

A neutron star in an artist’s impression. Source: NASA

Neutron stars are formed by collapses of giant stars accompanied by a supernova explosion. It compresses matter to an extreme state. As a result, an object with a diameter of a few tens of kilometers has a mass comparable to the mass of the Sun.

One of the characteristic features of neutron stars is their enormous rotational speed. Recently, astronomers were able to discover such an object, which rotates at a staggering 716 revolutions per second. 

The neutron star under discussion is located 26,000 light-years away from Earth near the center of the Milky Way. It is part of a binary system called 4U 1820-30. Its mass is 1.4 times that of the Sun, with a diameter of only 12 kilometers.

Astronomers were able to measure the rotation speed of the neutron star due to the presence of its companion. It is a white dwarf that orbits around it with a period of only 11 minutes. This makes 4U 1820-30 a system with the shortest known orbital period to date.

Because of this proximity, the neutron star pulls material away from the white dwarf. When enough material accumulates on its surface, a powerful explosion occurs. During it, the neutron star becomes 100,000 times brighter than the Sun, releasing huge amounts of energy. The NICER X-ray telescope installed aboard the ISS was able to record these flares, which drew the attention of astronomers to the system. In later observations, they were able to measure the rotational speed of the neutron star.

To date, the neutron star in the 4U 1820-30 system is one of the fastest rotating objects ever observed in the Universe. Only another neutron star PSR J1748-2446, located in the globular cluster Terzan 5 about 18,000 light-years from Earth, can be matched for rotational speed.

You can also read about how the Chandra telescope managed to map out danger zones for emerging exoplanets.

Provided by Phys.org