Helix Nebula

The Helix Nebula, also known as NGC 7293, is a wreath placed by nature around a dying star. Nearing the end of its life and running out of nuclear fuel, the star in the center of the nebula has blown off its outer atmosphere. The blue-green interior color of the nebula is caused by oxygen emission; farther out the red color is caused by hydrogen emission. Our Sun will likely meet the same fate in about five billion years. This image was made with the 0.8-meter Telescope at McDonald Observatory, with the Prime Focus Corrector instrument. Credit: Tom Montemayor/McDonald Observatory.