NASA's James Webb Space Telescope (JWST) has provided unprecedented insights into the Apep star system, a triple-star system located in the constellation Norma. This system comprises two Wolf-Rayet stars—a type of massive, hot star nearing the end of its life—and a distant supergiant star. JWST's observations have unveiled a complex structure of four coiled dust shells surrounding the central binary stars, a phenomenon not previously observed in such detail.
The dust shells are formed by the interaction of the stellar winds from the two Wolf-Rayet stars. As these stars orbit each other, their powerful winds collide, creating a dense, cool environment where carbon-rich materials condense into dust. This process results in the formation of spiral-shaped dust shells, resembling a pinwheel nebula. The JWST's Mid-Infrared Instrument (MIRI) captured these structures, highlighting the intricate dynamics of the system.
Combining JWST's mid-infrared data with observations from the European Southern Observatory's Very Large Telescope (VLT), astronomers have refined the orbital parameters of the central binary stars. The data indicate that the two Wolf-Rayet stars orbit each other approximately every 190 years, with each close pass lasting about 25 years. During these periods, the stars emit significant amounts of carbon-rich dust, contributing to the formation of the observed dust shells.
Additionally, JWST's observations have confirmed the presence of a third star in the system—a massive supergiant. This star's gravitational influence carves cavities into the expanding dust shells, adding complexity to the system's structure. The interaction between the three stars in Apep provides valuable insights into the processes of dust formation and the evolution of massive star systems.
Understanding systems like Apep is crucial for astrophysics, as they offer a window into the life cycles of massive stars and the mechanisms behind dust production in the universe. The detailed observations made by JWST not only enhance our knowledge of such systems but also contribute to our broader understanding of stellar evolution and the chemical enrichment of galaxies.