Astronomy Picture of the Day

Explanation: A familiar sight to sky enthusiasts with even a small telescope, the Ring Nebula (M57) is some 2,000 light-years away in the musical constellation Lyra. The central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. This remarkable composite image includes narrowband image data recording the Ring's atomic hydrogen emission (shown as violet) in visible light and molecular hydrogen emission (shown as red) at near infrared wavelengths. The much more distant spiral galaxy IC 1296 is also visible at the upper right.