NGC7293 is a planetary nebula in Aquarius. It, and the hot white dwarf at it's very centre, are all that remains of a fairly ordinary star about 650 light-years away. The outer layers of the star have spread out into a broad nebula, and the superdense Earth-sized remnant of the star illuminates and ionises the gas to produce a pretty nebula about 2.5 light-years in diameter.