M57
M 57 · Ring Nebula — the hourglass, seen pole-on
The sky's most famous smoke ring is a matter of viewing angle. M 57, the Ring Nebula in Lyra, is like the Dumbbell M 27 the cast-off shell of a Sun-like star — spatially an hourglass, except that here we look almost exactly onto its pole and see the opening as a ring. The article on planetary nebulae places both viewing angles side by side; this image is its second exhibit, small but complete.
The nebula was discovered in January 1779, when Charles Messier and Antoine Darquier de Pellepoix independently followed the same comet. Darquier compared the little disk to a "fading planet" — exactly the sort of description from which William Herschel shortly afterwards made the misleading class name. After M 27 it was the second planetary nebula ever found.
The colors are the same ionization map as in the Dumbbell. Inside, doubly ionized oxygen gas [O III] glows turquoise where the central star's radiation arrives hardest; the red fringe is recombining hydrogen at the cooler edge. The ring measures a good arcminute across — at a distance of about 2,500 light-years (the Gaia parallax of the central star) that corresponds to roughly one light-year in diameter. The shell keeps expanding; its visible age is a few thousand years.
The culprit is in the picture. Exactly at the ring's center stands a point of nearly 16th magnitude (marked in the overlay): the newly formed white dwarf driving the show. That a digital SLR on an 8-inch Newtonian captures it is the quiet triumph of this small image.
And a bonus for looking closely: below and to the right of the ring, the barred spiral galaxy IC 1296 shimmers as a tiny elongated smudge — more than 200 million light-years away, almost a hundred thousand times farther than the nebula in front of it. A field twenty arcminutes across, and the depth axis reaches from the dying neighboring star out into the distant universe — projection in its most extreme form.
Where in the sky
The rectangle is this image's real field of view, with its measured rotation — not a symbol. Constellation figures and star positions come from SIMBAD.
2 entries sit within 24° of each other here — click a field to jump to it.
Crops
The ring
The ring in detail — an hourglass from above
6.0′ × 4.3′·18h 53m 34.84s +33° 01′ 49.9″
A good arcminute of nebula, a light-year across: inside the turquoise [O III], outside the red hydrogen fringe — the same layering as in the Dumbbell, which appears twenty times larger, only seen here from the pole. At the center stands, clearly recognizable, the white dwarf of barely 16th magnitude.
That the ring is not dark inside but filled with turquoise across its face betrays the third dimension: we are looking through the open axis of the hourglass right into the glowing shell.
IC 1296
IC 1296 — the galaxy behind the nebula
4.6′ × 3.5′·18h 53m 18.92s +33° 04′ 01.1″
The inconspicuous elongated shimmer is a barred spiral galaxy: IC 1296, more than 200 million light-years away. Its light had already been traveling for millions of years when the Ring Nebula was still an ordinary star — and it has traveled about a hundred thousand times as long as the nebula's light.
Nebula and galaxy stand only a few arcminutes apart and yet worlds separate them: this gallery's most vivid example that an image field is not a map but a line of sight.
Acquisition and processing
The image comes from this gallery's early Newtonian period: the astrometrically measured image scale of 1.05″/pixel is exactly that of the GSO 8″ f/4 Newtonian at 800 mm focal length with the Canon EOS 70D — the same combination as for the 2016 Orion Nebula. The file name records sub-exposures of 120 s; the original acquisition logs (frame count, date, total exposure) are no longer preserved and are deliberately not reconstructed or guessed here.
What survives is the processed version: stars and nebula were treated separately (the file name carries the starless intermediate step) and reassembled; the published AVIF file was output in Photoshop/Camera Raw in 2026 and shows a crop of 1,189 × 793 pixels.
The published file was solved astrometrically and independently: 96 Gaia reference stars, residual error 0.51″, scale 1.0503″/pixel, field 20.8′ × 13.9′. Crop coordinates, size figures and the object markers are computed from this solution and not placed onto the preview by eye.