This is a planetary nebula, a star that has ‘blown up’. The expanded gases are ionised by radiation from the star’s remnant and this creates a beautiful display for us to view. M57 is quite easy to view, even with a relatively small telescope and is well worth the effort.
As ever click on the image for details & larger imagery.
I followed my by now standard development process using Iris for registration, stacking & stretching, Photoshop for levels adjustment & noise control and finally Lightroom for final cleanup & fileing. One additional process was used for this image, a Richardson Lucy deconvulution was carried out in Iris.