What created the unusual cosmic sculpture like a taijitu, where yin and yang interlock? The stars. The James Webb Space Telescope of the National Aeronautics and Space Administration (NASA) has, for the first time, revealed four spiral dust shells around a pair of Wolf-Rayet stars known as Apep in the constellation Norma in the southern sky in 2024.
A Wolf-Rayet star is a star 20 times heavier than the sun, in a phase where carbon and oxygen produced by nuclear fusion in the core are being transported to the star's surface. About 164 are known in the Milky Way. In 1867, Charles Wolf and Georges Rayet first established the theory, giving the star its name. Wolf-Rayet stars are in a relatively late stage of a star's life and are sometimes thought to be just before a supernova explosion.
The James Webb Space Telescope observed Wolf-Rayet stars in unprecedented detail in infrared. According to the observations, this peculiar shape appears to have formed as two massive Wolf-Rayet stars orbit each other on a 190-year cycle and, during a 25-year close pass, eject new shells of dust and gas. The holes in these shells are thought to be produced by a third orbiting star. The dance set off by the stars' dust will continue for hundreds of thousands of years and will likely end when one of the massive stars exhausts its internal nuclear fuel and explodes as a supernova, triggering a gamma-ray burst.