NGC 6302 is a beautiful example of a planetary nebula formed when a bloated red giant star transformed into a tiny white dwarf, belching about half its mass into space in the process.
This dramatic image looks like some vast cosmic eruption, and that impression is entirely correct. We’re looking at a dying star, perhaps five times the mass of our Sun as it blasts its outer layers into space. Designated NGC 6302 and often called the Butterfly Nebula, this is an example of a planetary nebula. Once a vast red giant, the star at the nebula’s centre is losing mass in ferociously violent stellar winds as it transforms itself into a white dwarf. In this case the central star is among the hottest known. The fastest and strongest winds erupt from the star’s poles, while the outflow from its equator is relatively gentle, giving the nebula the hourglass shape common among planetary nebulae. This nebula is found in the constellation Scorpius and lies nearly 4000 light years (1226 parsecs) from our Sun, which itself will go through a similar phase some seven billion years from now.