A rare view of a Wolf-Rayet star – among the most luminous, massive and fleetingly detectable stars known – was one of the first observations made by NASA’s James Webb Space Telescope, the European Space Agency (ESA) and the Canadian Space Agency. , in June 2022. Using their powerful infrared vision instruments, researchers were able to observe the star WR 124 in unprecedented detail. The star is 15,000 light-years away in the constellation of Sagittarius.
The telescope captures the star WR 124 in an unprecedented degree of detail
Massive stars go through their life cycles very quickly, with only a few of them going through a brief Wolf-Rayet phase before going supernova, making Webb’s detailed observations of this rare phase invaluable for scientists. These types of stars are in the process of shedding their outer layers, resulting in their characteristic halos of gas and dust.
The star WR 124 is 30 times the mass of the Sun and has so far spewed out material equivalent to ten suns. As the ejected gas recedes and cools, it forms cosmic dust that glows in the infrared light detectable by Webb.
As the ejected gas recedes and cools, it forms cosmic dust that glows in the infrared light detectable by Webb.
The origin of cosmic dust that can survive a supernova explosion and contribute to the total “dust budget” of the universe is of great interest to astronomers for several reasons. Dust is an integral part of how the universe works: It can harbor forming stars, accumulate to create planets, and serve as a platform for the growth and agglomeration of molecules, including the building blocks of life on Earth.
Despite its many essential functions, the cosmos contains more than can be explained by astronomers’ current theories about its formation. The universe is running on a budget surplus of dust.
Webb opens up new possibilities for studying its details by looking at wavelengths of infrared light. The telescope’s near-infrared camera (NIRCam) balances the brightness of WR 124’s stellar core and the twisted features in the darker surrounding gas. The Mid-Infrared Instrument (MIRI) reveals the irregular structure of the nebula of gas and dust from the ejected material that now surrounds the star.
The universe runs on an excess of cosmic dust
Before Webb, astronomers didn’t have enough information to examine dust production in configurations like WR 124 and whether the grains were large and plentiful enough to survive the supernova and become a significant contribution to the total dust budget. Now these questions can be investigated with real data.
Stars like WR 124 also serve as an analogy to help scientists understand a crucial period in 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 commonplace in the current era, even on Earth.
Dying stars lose the building blocks that made up the early universe
Webb’s detailed image of WR 124 forever preserves a brief, turbulent moment of transformation and promises future discoveries that will reveal long-hidden mysteries of cosmic dust.
The James Webb Space Telescope is the world’s leading space science observatory. Webb will solve the mysteries of our solar system, look beyond the distant worlds around other stars, and explore the mysterious structures and origins of our universe and our place in it. Webb is an international program run by NASA with its partners: the European Space Agency (ESA) and the Canadian Space Agency (CSA).