Today’s image from the Hubble Space Telescope Advent Calendar:
The Butterfly Nebula, NGC 6302, is one of the brightest and most extreme planetary nebulae known. What resemble dainty wings are actually roiling cauldrons of gas heated to more than 36,000 degrees Fahrenheit. The gas is tearing across space at more than 600,000 miles an hour. A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. […] The glowing gas is the star’s outer layers, expelled over about 2,200 years. The “butterfly” stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.
More info about the nebula at HubbleSite