Planetary nebulae like the Red Spider Nebula form when ordinary stars like the Sun reach the end of their lives. After ballooning into cool red giants, these stars shed their outer layers and cast them into space, exposing their white-hot cores. Ultraviolet light from the central star ionises the cast-off material, causing it to glow. The planetary nebula phase of a star’s life is as fleeting as it is beautiful, lasting only a few tens of thousands of years. The central star of the Red Spider Nebula is visible in this image, glowing just brighter than the webs of dusty gas that surround it.

A large planetary nebula. The nebula’s central star is hidden by a blotchy pinkish cloud of dust. A strong red light radiates from this area, illuminating the nearby dust. Two large loops extend diagonally away from the centre, formed of thin ridges of molecular gas, here coloured blue. They stretch out to the corners of the view. A huge number of bright, whitish stars cover the background, also easily visible through the thin dust layers.] Links Science paper Annotated image Slider tool: Hubble and Webb’s views of NGC 6537 Image on ESA website Pan video Transition Video: Hubble and Webb’s views of NGC 6537 Space Sparks Episode

The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds flowing out from the central stars, have been measured in excess of 1,000 kilometers per second. These winds expand the nebula, flow along the nebula’s walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the featured false-color infrared picture by the James Webb Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer (Sagittarius). Its distance is not well known but has been estimated by some to be about 4,000 light-years.

The surprising nature of the nebula’s tremendously hot and luminous central star has been revealed by Webb’s NIRCam. In optical-wavelength images, such as from the NASA/ESA Hubble Space Telescope, the star appears faint and blue. But in the NIRCam images, it shows up as red: thanks to its sensitive near-infrared capabilities, Webb has revealed a shroud of hot dust surrounding the central star. This hot dust likely orbits the central star, in a disc structure. Though only a single star is visible in the Red Spider’s heart, a hidden companion star may lurk there as well. A stellar companion could explain the nebula’s shape, including its characteristic narrow waist and wide outflows. This hourglass shape is seen in other planetary nebulae such as the Butterfly Nebula, which Webb also recently observed. Webb’s new view of the Red Spider Nebula reveals for the first time the full extent of the nebula’s outstretched lobes, which form the ‘legs’ of the spider. These lobes, shown in blue, are traced by light emitted from H2 molecules, which contain two hydrogen atoms bonded together. Stretching over the entirety of NIRCam’s field of view, these lobes are shown to be closed, bubble-like structures that each extend about 3 light-years. Outflowing gas from the centre of the nebula has inflated these massive bubbles over thousands of years.  Gas is also actively jetting out from the nebula’s centre, as these new Webb observations show. An elongated purple ‘S’ shape centred on the heart of the nebula follows the light from ionised iron atoms. This feature marks where a fast-moving jet has emerged from near the nebula’s central star and collided with material that was previously cast away by the star, sculpting the rippling structure of the nebula seen today.  The observations used to create this image come from Webb GO programme #4571 (PI: J. Kastner) as part of a joint Chandra-JWST observing programme, which aims to understand how bipolar planetary nebulae like the Red Spider Nebula are shaped by the outflows and jets that emerge from the stars at their cores.