While the sky is full of planetary nebulae, few are as striking as M57, The Ring Nebula in Lyra. At a distance of 2300 light years, it is close enough to be easily viewed in small telescopes, as well as photographed in great detail by advanced amateurs and professionals. It's invariably where I start my visual sessions in the summer. Easy to find, situated between Sulafat and Sheliak at the end of Lyra opposite Vega, it makes a great object for sharing with casual observers as well. We've all heard gasps from someone as they exclaim "It looks like a doughnut!"
M57 is not only visually interesting, but it's scientifically important as well. The bright portion of the planetary nebula is about one light year in diameter, and its proximity has made it a prime subject of stellar evolution
research. Studies have shown that when observing M57, we are probably actually looking down the length of a cylindrical structure, rather than the doughnut shape it appears to have in the eyepiece. It has considerable internal structure, including vaguely spiral lanes of red-glowing gasses contrasted with the beautiful blue and cyan gasses in the cylinder's center.
High resolution images show even more structure, including dark globules and radial spokes emanating from the beautiful example of a white dwarf directly in the center of it all.
The famous ring shaped nebulosity is surrounded by a much
fainter envelope of older planetary gasses. This envelope is difficult to photograph. This image shows a good deal of it, but not all of it, and not in much detail.
Though M57 is near the plane of the Milky Way, the field contains plenty of galaxies, including the beautiful barred spiral IC 1296 and a number of fainter background galaxies.
Image acquired at Prairie Sky Observatory, a facility of Twin City Amateur Astronomers (tcaa.us).
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