NGC 2392 is often called "the Eskimo nebula" because it looks a bit
like a face peering out from the hood of a furry parka. This object is the
result of a sun-like star exhausting much of its hydrogen and helium
fuel, puffing out into a giant star, and then shedding its outer layers
into space to be recycled into new stars and planets and perhaps life. Our
sun will go through a similar process in about 5 billion years. NGC 2392
probably sent out its bubbles of stellar gas only about 10,000 years ago;
that bubble is expanding, and ultraviolet radiation from the small white
"dwarf" star that is left in the middle ionizes the gas and sets it glowing.
The Eskimo nebula is in the constellation Gemini (and so is up high on the cold
winter nights of January and February, making the parka appearance appropriate),
and is about 3000 light years from earth.
(This image is cropped from the full frame)
Exposure: 6 x 5 minutes each of red, green, blue
Telescope: 12.5" Hyperion