The Ring Nebula, M57 in Lyra, a planetary nebula with a white dwarf star at the centre. Surely a candidate for one of the most beautiful and intriguing objects in the night sky.
M57 Ring Nebula, 2016-08-27. Taken with my Meade LX-90 telescope, 10x25s 2000mm f/10 R0.62 ISO4000. Image © R.Powell
A planetary nebula is what remains when a star similar to the Sun reaches the end of its life and blows away its outer envelope, leaving a white dwarf star at the centre.
The size of M57 is about 1.4 arc-minutes (about 0.6 light years) at a distance of 1400 light years and a visual magnitude of +8.8.