Astronomy Picture of the Day

Explanation: This cosmic snapshot covers a field of view over twice as wide as the full Moon within the boundaries of the high-flying constellation Cygnus. Made using astronomical narrowband filters, the image highlights the bright edge of a ring-like nebula traced by the glow of ionized hydrogen and oxygen gas. Embedded in the region's expanse of interstellar clouds, the complex, glowing arcs are sections of shells of material swept up by the wind from Wolf-Rayet star WR 134, brightest star near image center. Distance estimates put WR 134 about 6,000 light-years away, making this telescopic frame over 100 light-years across. Shedding their outer envelopes in powerful stellar winds, massive Wolf-Rayet stars have burned through their nuclear fuel at a prodigious rate and end their final phase of massive star evolution in a spectacular supernova. But their stellar winds and final supernova explosion enrich the interstellar material with heavy elements to be incorporated in future generations of stars.