A small, incredibly dense star thousands of light-years from Earth is behaving like a celestial whirlwind, unleashing bursts of energy comparable to repeated atomic bombs while spinning at a dizzying pace. This remarkable discovery, made using NASA’s NICER telescope, reveals one of the fastest-spinning objects ever observed.
This extraordinary object is a neutron star, the remnants of a massive star’s core collapse. Located within the X-ray binary system 4U 1820-30, it spins a staggering 716 times per second. This rapid rotation is coupled with powerful thermonuclear bursts triggered by material drawn from its companion star. These findings are detailed in a recent publication in The Astrophysical Journal.
A Cosmic Dance of Extremes
The neutron star resides approximately 26,000 light-years away in the Sagittarius constellation, near our galaxy’s center. 4U 1820-30 is an X-ray binary system, meaning it consists of two stars locked in a gravitational embrace: a normal star and a collapsed star—either a white dwarf, neutron star, or black hole. In this instance, the rapidly spinning neutron star is partnered with a white dwarf roughly the size of Earth. Their orbital dance is incredibly swift, with the white dwarf circling the neutron star every 11 minutes—the shortest known orbital period for such a system.
This close proximity creates dramatic consequences. The neutron star’s immense gravity siphons material from its white dwarf companion. As this material accumulates on the neutron star’s surface, it triggers powerful thermonuclear bursts, each comparable to an atomic bomb detonation.
Unprecedented Energy Release
These bursts are far from subtle. During these events, the neutron star’s brightness surges to 100,000 times that of our Sun, releasing an incredible amount of energy. “We are dealing with very extreme events,” explains Jerome Chenevez, associate professor at the Technical University of Denmark and co-author of the study. “By studying them, we gain new insights into the exciting life cycles of binary star systems and the formation of elements in the universe.”
Observing the Chaos
NASA’s Neutron star Interior Composition ExploreR (NICER), mounted on the International Space Station, plays a crucial role in observing these extreme phenomena. Between 2017 and 2021, NICER observed 15 thermonuclear X-ray bursts from 4U 1820-30. These observations not only revealed the bursts but also the remarkable oscillations indicating the neutron star’s rapid spin.
A Record-Breaking Spin
“We were studying thermonuclear explosions from this system and then found remarkable oscillations, suggesting a neutron star spinning around its central axis at an astounding 716 times per second,” states Gaurava Jaisawal, lead author of the study and scientist at the Technical University of Denmark. This incredible speed places the 4U 1820-30 neutron star among the fastest-spinning objects ever observed, rivaled only by another neutron star, PSR J1748–2446.
Future Explorations
Further observations are planned to delve deeper into this unusual celestial pairing. These future studies promise to illuminate the processes by which these dead stars create such extraordinary cosmic chaos.
