The James Webb Space Telescope (JWST) has captured an unprecedented and stunning view of the Red Spider Nebula (formally known as NGC 6537), a planetary nebula located about 3,000 light-years away in the constellation Sagittarius. This new image, utilizing the telescope's powerful Near-Infrared Camera (NIRCam), has revealed intricate details of the dying star's final act, including its immense, elongated lobes—the cosmic "legs"—that stretch across three light-years each.
Anatomy of a Dying Star
The Red Spider Nebula is a classic example of a planetary nebula, a structure formed when a star similar in mass to our Sun reaches the end of its life.
Formation: As a Sun-like star runs out of fuel, it expands into a cool red giant. It then begins to shed its outer layers of gas and dust into space, exposing its incredibly hot, white-hot core.
The Glow: Ultraviolet radiation from this exposed core—which is one of the hottest stars known, with a surface temperature soaring above $250,000^\circ\text{C}$—ionizes the expelled gases, causing them to glow vividly. This beautiful, glowing phase is remarkably short-lived, lasting only a few tens of thousands of years in cosmic terms.
Key Discoveries from JWST's Infrared View
JWST's sensitive near-infrared capabilities have offered a view that far surpasses previous observations, such as those by the Hubble Space Telescope.
The 3-Light-Year-Long Legs: For the first time, the full extent of the nebula's two massive lobes, which form the "legs" of the spider, is visible. These lobes are shown to be closed, bubble-like structures that stretch approximately three light-years from the center. They are traced by the light emitted from molecular hydrogen ($\text{H}_2$), a component difficult to observe with optical telescopes. These enormous bubbles have been inflated over millennia by streams of gas bursting from the central star.
A Hot, Dusty Core: While previous Hubble images showed the central star as faint and blue in optical wavelengths, JWST's infrared view reveals it glowing red, shrouded by a thick cloud of hot dust. This dust is thought to be orbiting the central star in a disk-like structure.
A Hidden Companion Star: The nebula's distinct hourglass or narrow-waisted shape strongly suggests the presence of a hidden companion star that may be orbiting the visible central star. The gravitational influence of this unseen partner could be responsible for sculpting the ejected material into the nebula's characteristic bipolar form. This shape is also seen in other planetary nebulae, like the Butterfly Nebula.
Active Jets: The new image also captures evidence of active processes at the nebula's heart. An elongated, faint purple "S"-shape centered on the star traces the light from ionized iron atoms. This feature marks where a fast-moving jet has erupted from the central star and collided with previously ejected material, contributing to the nebula's rippling structure.
The JWST observations of the Red Spider Nebula are part of a program designed to understand how bipolar planetary nebulae are shaped by the powerful outflows and jets emerging from their stellar cores, often involving binary star systems.