The cosmic ring created by a dying starS

This tiny white dwarf and the shell of gas that surrounds it was once a star very much like our Sun, and the gas is positioned just right so that it looks like a faint, glowing ring in space.

Such collections of gas around white dwarfs are known as planetary nebulae. It's not a particularly accurate term, of course - it just happens that the first such phenomena to be observed happened to look like gas giant planets, and so the name stuck. This particular planetary nebula, named Shapley 1 after the astronomer Harlow Shapley, looks particularly unlike a gas giant.

Indeed, Shapley 1 is a particularly ghostly reminder of the fate that ultimately awaits our own Sun. Most of the mass of this Sun-like star has condensed into a sphere roughly the size of Earth. Considering you could fit more than a million Earths inside the Sun, you can imagine the tremendous density of the white dwarf. But while this husk of the former star will continue to burn for untold eons - seriously, we don't actually know how long white dwarfs endure, although estimates range anywhere from 10^15 to 10^200 years - the wispy gas that surrounds it will dissipate long before then.

Maybe it's just all that empty space between the ring of gas and the white dwarf, but somehow the fate of stars has never seemed quite so, well...hollow.

Via NASA. Image by the ESO.