JWST Wolf-Rayet Star

This rare sight is a super-bright, massive Wolf-Rayet star. Calling forth the ephemeral nature of cherry blossoms, the Wolf-Rayet phase is a fleeting stage that only some stars go through soon before they explode.

The star, WR 124, is 15,000 light-years away in the constellation Sagittarius. It is 30 times the mass of the Sun and has shed 10 Suns worth of material – so far. As the ejected gas moves away from the star and cools, cosmic dust forms and glows in the infrared light detectable by Webb.

The origin of cosmic dust that can survive a supernova blast is of great interest to astronomers for multiple reasons. Dust shelters forming stars, gathers together to help form planets, and serves as a platform for molecules to form and clump together, including the building blocks of life on Earth.

Stars like WR 124 also help astronomers understand the early history of the universe. Similar dying stars first seeded the young universe with heavy elements forged in their cores – elements that are now common in the current era, including on Earth.

The James Webb Space Telescope opens up new possibilities for studying details in cosmic dust, which is best observed in infrared wavelengths of light. Webb’s Near-Infrared Camera (NIRCam) balances the brightness of WR 124’s stellar core and the knotty details in the fainter surrounding gas. The telescope’s Mid-Infrared Instrument (MIRI) reveals the clumpy structure of the gas and dust nebula of the ejected material now surrounding the star.