Stingray Nebula

This Wide Field and Planetary Camera 2 image captures the infancy of the Stingray Nebula (Hen-1357), the youngest known planetary nebula. A planetary nebula forms after an aging, low-mass star swells to become a "red giant" and blows off some of its outer layers of material. As the nebula expands away from the star, the star's remaining core gets hotter and heats the gas until it glows. In this image, the bright central star is in the middle of the green ring of gas. A companion star is diagonally above it at 10 o'clock. A spur of gas (green) is forming a faint bridge to the companion star due to gravitational attraction. The nebula is as large as 130 solar systems, but at its distance of 18,000 light-years, it appears only as big as a dime viewed a mile away.