Free Astronomy Magazine May-June 2023

47 MAY-JUNE 2023 ASTRO PUBLISHING T he luminous, hot star Wolf-Rayet 124 (WR 124) is prominent at the center of the James Webb Space Telescope’s composite image com- bining near-infrared and mid-in- frared wavelengths of light. The star displays the characteristic diffraction spikes of Webb’s Near-Infrared Cam- era (NIRCam), caused by the physical structure of the telescope itself. NIR- Cam effectively balances the bright- ness of the star with the fainter gas and dust surrounding it, while Webb’s Mid-Infrared Instrument (MIRI) reveals the nebula’s structure. [NASA, ESA, CSA, STScI, Webb ERO Production Team] 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 tele- scope’s Mid-Infrared Instrument (MIRI) reveals the clumpy structure of the gas and dust nebula of the ejected material now surrounding the star. Before Webb, dust-loving astronomers simply did not have enough detailed information to ex- plore questions of dust production in environments like WR 124, and whether the dust grains were large and bountiful enough to survive the supernova and become a significant contribution to the overall dust budget. Now those questions can be investigated with real data. Stars like WR 124 also serve as an analog to help astronomers under- stand 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 com- mon in the current era, including on Earth. Webb’s detailed image of WR 124 preserves forever a brief, turbu- lent time of transformation, and promises future discoveries that will reveal the long-shrouded mysteries of cosmic dust. !