The neutron star in X-ray binary system 4U 1820-30 rotates 716 times per second, the fastest rate ever observed, according to an analysis of data collected by NASA’s Neutron Star Internal Composition Explorer (NICER). It is one of the rotating celestial bodies. 2017 and 2022.
Artist’s depiction of the X-ray binary star system 4U 1820-30 at the center of globular cluster NGC 6624. Image credit: NASA.
4U 1820-30 It is located approximately 26,000 light years from Earth in the constellation Sagittarius.
This X-ray binary star system is part of a metal-rich globular cluster called NGC6624.
It consists of two stars: a neutron star and a white dwarf companion. The latter orbits a neutron star every 11 minutes, making it the star system with the shortest known orbital period.
The 4U 1820-30 typically displays short bursts of X-rays that last only 10 to 15 seconds. This is likely due to the ignited helium-rich fuel burning out quickly on the surface.
“Due to its strong gravity, the neutron star pulls matter away from its companion star,” said Dr. Gaurava Jaisawal of DTU Space and colleagues.
“When enough material accumulates on the surface, a violent thermonuclear explosion occurs on the neutron star, similar to an atomic bomb.”
Astronomers observed 4U 1820-30 using NASA’s NICER X-ray telescope mounted outside the International Space Station.
“While studying thermonuclear explosions from this system, we discovered significant oscillations, caused by the neutron star rotating around its central axis at an astonishing speed of 716 times per second. “This suggests that the
“If future observations confirm this, the 4U 1820-30 neutron star would be one of the fastest rotating objects ever observed in the universe, rivaled by a star called PSR J1748-2446. There will only be another neutron star.”
From 2017 to 2021, NICER detected 15 thermonuclear X-ray bursts from 4U 1820-30.
This was one of the bursts that exhibited symptoms known as “thermonuclear burst oscillations,” which occur at a frequency of 716 Hz.
These bursts of oscillations match the rotational frequency of the neutron star itself, meaning it is rotating around its axis at a record speed of 716 times per second.
“During the burst, the neutron star becomes up to 100,000 times brighter than the Sun and releases an enormous amount of energy,” said DTU space researcher Dr. Jerome Cheneves.
“We are therefore working on very extreme events, and studying them will provide new insights into the existing life cycles of binary star systems and the formation of elements in the universe.”
of findings will appear in astrophysical journal.
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Gaurava K. Jaisawal others. 2024. A comprehensive study of the 4U 1820-30 thermonuclear X-ray burst by NICER: accretion disk interactions and candidate burst oscillations. APJ 975, 67; doi: 10.3847/1538-4357/ad794e
Source: www.sci.news
