A team of Chinese astronomers has discovered a new millisecond pulsar in the Messier 53 globular cluster using the FAST Aperture Spherical Radio Telescope (FAST), according to a research paper published June 16 on the prepress server. arXiv.

Pulsars are rotating neutron stars with strong magnetization that emit a beam of electromagnetic radiation. The fastest spinning pulsars with a rotation period of less than 30 milliseconds are known as millisecond pulsars (MSPs). Astronomers suggest they form in binary systems, when the more massive component first transforms into a neutron star, which then spins upward through the accumulation of matter from the secondary star.

Globular clusters (GCLs) are collections of closely related stars orbiting galaxies. They have an extremely dense stellar environment, making them excellent sites for the formation of X-ray binaries of millisecond pulsars.

Located about 58,350 light-years away, Messier 53 (also known as M53 or NGC 5024) is the most distant pulsar known. The cluster has an age of about 12.67 billion years, a mass of about 826,000 solar masses, and a metallicity of -2.1, making it one of the metal-poorest humic substances in the Milky Way. Four pulsars have been detected in Messier 53 to date, and three of them are MSPs.

Now a team of astronomers led by Yujie Liang of Beijing Normal University in China reports the discovery of another MSP in this cluster. Detection was carried out using the central beam of the 19-beam L-band of the FAST receiver.

“M53 observations were launched on 30 November 2019 as a pilot study for the FAST GC pulsar survey and the SP2 4 project (Pan et al. 2021),” the researchers wrote in the paper.

The newly discovered pulsar was named PSR J1312+1810E (or M53E). It has a rotation period of about 3.97 milliseconds and a distribution measure of about 25.88 pc/cm.³. The orbital period of M53E was 2.43 days.

The companion object in the system is most likely a white dwarf with an estimated mass of at least 0.18 solar masses. It turned out that the intensity of the surface magnetic field of M53E is no more than 140 million Gauss, and the characteristic age of the pulsar is more than 13 billion years.

In addition to discovering M53E, the FAST observations also allowed Lian’s team to investigate three other MSPs in Messier cluster 53. They discovered that one of them is an isolated pulsar, and the other two are white dwarf binary systems with a slightly larger mass than M53E. Overall, the results show that the characteristics of this pulsar population are similar to the MSP population in the Milky Way disk. Source