One of the closest planetary nebulae to Earth, the Helix Nebula, has become a favorite among astronomers using ground- and space-based telescopes to study the final moments of a dying star in detail. The NASA/ESA/CSA James Webb Space Telescope has now zoomed in on this familiar object, offering its clearest infrared look yet.
It gives us a closer view of the possible ultimate fate of our own Sun and planetary system. In Webb’s high-resolution look, the composition of gas emitted by a dying star comes into perfect focus. The image is not only fascinating, but it explains how stars recycle their material back into the universe, seeding future generations of stars and planets.
In Webb’s NIRCAM (Near-Infrared Camera) image, comet-like pillars with extended tails trace the perimeter of the inner region of the expanding sphere of gas. Here, strong winds of hot gas from the dying star are slamming into the cooler ball of dust and gas that was shed earlier in its life, sculpting the nebula’s remarkable structure. This happens when a lighter, faster moving substance pushes into a heavier, slower moving substance, like oil tries to push into water.
The iconic Helix Nebula has been imaged by numerous ground- and space-based observatories in the nearly two centuries since its discovery. Webb’s near-infrared view of the target compared to an ethereal image from the NASA/ESA Hubble Space Telescope brings these knots to the forefront. Additionally, the new near-infrared form shows a clear transition between the hottest gas to the coolest gas as the shell expands out from the central white dwarf.
This glowing white dwarf, the remnant core of a dying star, lies just out of the frame of the web image, right in the middle of the nebula. Its intense radiation illuminates the surrounding gas, creating a rainbow of features: hot ionized gas near the center (top of the web image), cooler molecular hydrogen farther away, and protective pockets where more complex molecules can begin to form within the dust cloud. This interaction is important, because it is the raw material from which new planets may one day form in other star systems.
In Webb’s image of the Helix Nebula, the color represents this temperature and chemistry. A touch of blue marks the hottest gas in this region, which is activated by intense ultraviolet light. Moving away, the gas cools into yellow regions where hydrogen atoms combine into molecules. At the outer edges, red tones trace the coldest material, where the gas begins to thin and dust may form. Together, the colors show a star’s last breath turning into the raw material for new worlds, adding up to the wealth of knowledge gleaned from the Web about the origins of planets.
The Helix Nebula is located 650 light years from Earth in the constellation Aquarius. It remains a favorite among stargazers and professional astronomers alike due to its close proximity to Earth and attractive appearance.
[Image description: A closeup of a small section of the Helix Nebula, an expanding shell of gas and dust. Thousands of orange and gold comet-like pillars stream upward from the bottom, like thin liquid blown up a sheet of glass. These pillars are around the circumference of the arced shell, which forms a partial orange semi-circle at the bottom. The pillars are more numerous and denser at the bottom, and darker red. They fade to orange and then yellow in the arc. In the top two-thirds, they are thinner and more golden, and it’s easier to see the black background of space. Several bright blue stars, some with diffraction spikes, are scattered throughout. A few larger stars are on the right side.]
