The Ring Nebula Is Not a Ring | M57 in 4K

Is the Ring Nebula a ring? no — newer observations show a deep shell seen almost pole-on, not a flat ring. You have seen this picture. A smoke ring in space, a tiny star at its centre — and the picture is playing a trick on you. Tonight we go there, and we turn it on its side. The Ring Nebula, Messier 57, is a planetary nebula in the constellation Lyra — the glowing outer layers cast off by a dying star, and in NASA's words the best-known planetary nebula in the sky. 'Planetary nebula' is a two-hundred-year-old misnomer: in small telescopes these round glows looked like the disks of planets. Search for Ring Nebula in Universe Finder, select it, and fly. The map's flight is symbolic — it finds the address; the telescopes show the place. The Ring Nebula is about 2,500 light-years away — 790 parsecs, measured from the Gaia parallax of its central star. Its light takes about 2,600 years to reach Earth, so we see the Ring Nebula as it was some twenty-six centuries ago. In Hubble's view the colours trace elements — helium in the blue centre, hydrogen and oxygen in the inner ring, nitrogen and sulfur in the red rim; Webb's infrared images are false-colour throughout. The bright ring is roughly a light-year across; the faint outer halo spans about three light-years. Hubble observations model the bright ionized gas as barrel-like. Newer carbon-monoxide data trace a thin molecular envelope around it, closer to a truncated ellipsoid seen almost pole-on. Turning the nebula on its side is a visualization, not a 3-D photograph: the barrel-like form represents the bright ionized region, while the newer carbon-monoxide model adds a thin, truncated ellipsoidal molecular envelope around it. Picture a deep, open-ended shell, with bright ionized gas inside and a thin molecular skin around it. Look almost straight down its axis, and the rim becomes the Ring. The star that shed this nebula was somewhat heavier than the Sun — roughly one and a half to two solar masses by the models; about 0.58 solar masses of it remains as the core. The age depends on which layer and model is measured: about 4,000 years for the bright ionized shell, and about 6,000 years for the surrounding molecular envelope. The shell is still expanding at about 20 to 25 kilometres per second. The faint central star is the exposed core of the star that made the nebula: about 135,000 kelvin, some three hundred times the Sun's luminosity, and cooling toward a white dwarf. From Webb's images astronomers estimate roughly 20,000 dense globules of molecular hydrogen in the shell — about 17,500 found by an algorithm, about 25,000 by a manual count scaled to the whole ring — each about 150 times the Earth–Sun distance across. About ten faint, evenly spaced arcs outside the main ring suggest a low-mass companion orbiting the dying star roughly every 280 years, at about the Earth–Pluto distance — inferred from the arc spacing, not yet seen directly. A faint red dwarf shares the central star's motion at about 15,000 times the Earth–Sun distance; with the inferred inner companion, the system is likely a triple. A star like the Sun ends this way too: NASA expects the Sun to swell into a red giant and become a white dwarf in about five billion years — though the Ring's star was somewhat heavier than ours. Antoine Darquier de Pellepoix and Charles Messier both found the Ring Nebula in 1779 while tracking a comet through Lyra. Look for Vega, then the small parallelogram of stars beside it: the Ring Nebula lies halfway between the parallelogram's two southern stars, Sheliak and Sulafat. At magnitude 8.8, binoculars may show a faint point; use a telescope to resolve the smoke-ring shape. Open the Tonight panel in Universe Finder and use your location to see when the Ring Nebula is above your horizon. Choose Find in my sky for the real direction, or Show in 3D to return to the flight. Every number in this film is measured or labelled as an estimate, and every image carries its credit. The sources are in the description. Where should we fly next — Jupiter, or the Crab Nebula? Tell us below. Fly. Explore. Discover. UniverseFinder.com.