Skull Nebula

Also known as NGC 246, this planetary nebula is an envelope of gas surrounding a dying star. Expelled over a period of thousands of years, the lovely, intricate nebula is the outer atmosphere of the stellar body. The expanding outer atmosphere is interacting with the gas and dust in the interstellar medium, while the star itself, the fainter member of the binary star system seen at the nebula's center, is entering its final phase of evolution, becoming a dense, hot white dwarf. Star and nebula are moving rapidly toward the top of the detailed view, as suggested by the nebula's brighter, upper, leading edge.