New observations from NASA’s James Webb Space Telescope are offering the clearest look yet at a rare and little-studied nebula known as PMR 1, nicknamed the “Exposed Cranium” nebula for its resemblance to a brain inside a transparent skull.
A nebula is a cloud of gas and dust in space, often formed when stars shed material near the end of their lives. In this case, Webb captured PMR 1 using both near-infrared and mid-infrared instruments, revealing new structure and activity around a star approaching its final evolutionary stages.
The James Webb Space Telescope, the most advanced space observatory ever launched, is designed to study the universe in infrared light. This allows it to see through dust clouds and observe processes that are hidden from traditional optical telescopes. Webb’s observations of PMR 1 build on earlier infrared detections made by NASA’s retired Spitzer Space Telescope, but with far greater clarity and resolution.
Two Infrared Views of a Dying Star
Webb observed the nebula using NIRCam for near-infrared light and MIRI for mid-infrared light, with each instrument revealing different aspects of the structure.
In near-infrared images, the nebula’s outer shell appears sharply defined, while its inner clouds glow with warm tones. A dark vertical lane runs through the center, dividing the nebula into two lobes and giving it its distinctive brain-like appearance. Stars and distant galaxies are visible through and around the outer shell.
Mid-infrared images tell a different story. Dust within the nebula glows more strongly, the inner regions appear denser, and the central dark lane becomes less uniform. Webb’s data also suggests that material is being pushed outward from the central star, particularly at the top of the nebula, indicating active outflows.
Together, these views show how gas and dust are distributed across different phases of the nebula’s formation.
A Snapshot of Stellar Evolution in Progress
Astronomers believe PMR 1 consists of an outer shell of gas expelled earlier in the star’s life and a more complex inner region shaped by later activity. The prominent central lane may be linked to episodic outbursts from the dying star, where material is ejected in opposing directions.
What happens next depends on the star’s mass. A massive star may eventually explode as a supernova, while a Sun-like star will continue shedding material until only a dense white dwarf remains. Webb has captured a brief moment in this process, offering insight into how stars reshape their surroundings as they age.
As the world’s leading space science observatory, the James Webb Space Telescope is enabling scientists to study short-lived and previously obscured stages of cosmic evolution. Observations like those of the Exposed Cranium nebula demonstrate Webb’s ability to reveal fine detail in complex environments, helping researchers better understand how stars live, change, and ultimately influence the structure of the universe.
Leave a Reply