By observing beyond visible wavelengths with infrared imaging, astronomers can trace both ionized gas and cool dust in evolving stellar systems. The James Webb Space Telescope now pushes this capability further than any previous observatory. The recent observation of PMR 1 showcases how multi-wavelength infrared data can resolve the geometry and composition of a dying star’s envelope with exceptional clarity.

In February 2026, NASA, ESA, and the Webb team released a combined NIRCam and MIRI image of PMR 1. The object represents a late stage in stellar evolution, when a star expels its outer layers into space. JWST’s data reveal a structured nebula divided by a distinct dark lane and surrounded by layered material. These features provide direct evidence that mass loss in evolved stars proceeds in complex and often asymmetric ways.

A brief look at PMR 1

PMR 1 formed when an aging star began ejecting its outer envelope through strong stellar winds. According to the official JWST release, the nebula consists of gas and dust expelled during a late evolutionary stage. This material now surrounds the central star and emits strongly in the infrared.

Stars in this phase undergo rapid structural changes. Nuclear burning shifts in the core, and the outer layers become unstable. As a result, the star drives material outward in powerful outflows. These winds carry chemically enriched matter into the surrounding interstellar medium.

Consequently, objects like PMR 1 play a critical role in galactic evolution. The expelled material contains heavy elements forged inside the star. Over time, this matter mixes into molecular clouds, where new stars and planetary systems form. Thus, the death of one star seeds the birth of others.

However, the precise evolutionary path of PMR 1 remains uncertain. Scientists note that the central star’s mass has not yet been firmly determined. If the star resembles the Sun in mass, it will likely produce a planetary nebula and eventually settle as a white dwarf. If it is substantially more massive, it could follow a more energetic path that culminates in a supernova. At present, the available data do not resolve this question.

JWST’s dual-instrument view

JWST observed PMR 1 using two of its core instruments: NIRCam and MIRI. Each instrument probes a different portion of the infrared spectrum. Together, they provide a comprehensive physical view of the nebula.

NIRCam operates in the near-infrared regime. These wavelengths trace relatively warmer gas and reveal fine structural detail. In the PMR 1 image, NIRCam data show sharply defined inner regions and intricate filaments. The brighter central areas likely represent more recent mass-loss events.

MIRI extends the view into the mid-infrared. This wavelength range is particularly sensitive to cooler dust grains. In PMR 1, MIRI reveals a broader and more diffuse envelope surrounding the inner structure. The mid-infrared emission highlights material that earlier optical observations could not fully detect.

When astronomers combine these datasets, they separate emission from ionized gas and thermal dust. This layered perspective allows researchers to analyze temperature gradients and spatial distribution across the nebula. NASA and ESA emphasize that such multi-wavelength capability represents one of JWST’s defining strengths. Instead of relying on multiple observatories, scientists can now study hot and cool components within a single integrated dataset.

The dark lane that splits the nebula

One of the most prominent features in PMR 1 is the narrow dark lane that divides the nebula vertically. This structure separates the object into two opposing lobes. The lane likely marks a dense equatorial region where material blocks emission from behind it.

Such configurations often indicate asymmetric mass loss. Rather than ejecting material uniformly in all directions, the star appears to have expelled matter preferentially along specific axes. This process can produce hourglass-shaped nebulae.

JWST’s resolution reveals that the two lobes are not perfectly symmetrical. Subtle differences in brightness and texture suggest that the outflows changed over time. These variations imply that the star experienced multiple ejection phases, each contributing to the current morphology.

Moreover, scientists report that material near the upper portion of the nebula appears pushed outward. This pattern may indicate the influence of jet-like outflows. Jets can carve cavities through previously ejected material and enhance the structure. If confirmed through further study, PMR 1 would join a growing list of evolved nebulae shaped by collimated flows.

Dust, gas, and the record of mass loss

Infrared observations allow astronomers to probe regions hidden from optical telescopes. Dust absorbs visible light but emits efficiently at longer wavelengths. JWST provides a clearer view of the physical conditions within PMR 1. Near-infrared emission traces ionized gas located closer to the central star. These regions appear brighter and more structured in the NIRCam data. They likely correspond to relatively recent episodes of mass loss.

In contrast, the mid-infrared emission recorded by MIRI reveals cooler dust distributed across a wider area. This dust may represent material expelled during earlier phases. The layered appearance suggests that the star did not shed its envelope in a single event. Instead, it likely underwent successive periods of enhanced mass loss.

NASA and ESA scientists stress that analyzing these layers helps reconstruct the object’s evolutionary timeline. By estimating dust temperatures and spatial extent, researchers can infer changes in mass-loss rate. Furthermore, interactions between faster and slower winds may produce shock fronts. Some of the filamentary features seen in the near-infrared data could trace these collisions.

Clear skies!

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