Purple petals, an eerie purplish eye or tire glow in this image from the European Southern Observatory.
IC 5148, or the Spare Tire Nebula, is a planetary nebula with a diameter of just a couple of light-years. It is one of fastest expanding planetary nebula known to astronomers, growing at more than 50 kilometers per second. Planetary nebulae have nothing to do with planets. In the 19th century, astronomers searching for planets observed objects that looked similar to the outer gas giants Uranus and Neptune. Stars about the same size or slightly larger than our Sun will become planetary nebula at the end of their lives. As these stars burn the last of their hydrogen fuel, they begin to puff up and throw off their outer layers. Blistering ultraviolet radiation from the exposed hot white dwarf excites atoms in the expanding ring of material causing it to glow. While beautiful, planetary nebulae are a short-lived stage in a star’s life. Eventually the glowing shell will fade away.
IC 5148 is found about 3,000 light-years from Earth toward the southern constellation Grus, the Crane.