NGC6781 is a lovely planetary nebula that seems to be much ignored by amateur and professional astronomers alike, and even Wikipedia is at a loss with a single line! The only image from professional equipment I found that was somewhat inspiring was an old image from ESO in 2009
https://www.eso.org/public/images/ngc6781-potw/ . If anyone knows of a better image, please let me know. And finally, I could not find anyone who had tried to name this wonderful planetary nebula, which looks quite similar to the famous Ring Nebula in some ways, but that name is already taken. Unlike the more famous Ring Nebula, it looks like the interior of this ring leads to another universe, glowing in the green-blue light so different than the sky around it. For a name "The Ring of Fire Portal" seems to suite it, perhaps just one of many tunnels into other dimensions? And despite the apparent ring aspect, we are actually looking down a cylindrical tunnel, almost, but not quite perfect aligned toward us (the elliptical nebulosity shows the slight tilt).
As with other planetary nebula, this image shows the ultimate fate of our own sun, for stars that are not massive enough to explode in all their glory as a supernova, but rather expel gas in wave after wave, forming here a colorful shell, as later gas plows into gas that was ejected earlier, all of it excited by UV radiation from the hot white dwarf that is the remains of this dying star. The nebula is about 2 light years across, and two thousand light years distant in space-time.
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