NGC 7293: The Helix Nebula

Explanation: A mere seven hundred light years from Earth toward the constellation Aquarius , a star is dying. The once sun-like star's last few thousand years have produced the Helix Nebula . Also known as NGC 7293, the cosmic Helix is a well studied and nearby example of a Planetary Nebula , typical of this final phase of stellar evolution. Combining narrow band data from emission lines of hydrogen atoms in red and oxygen atoms in blue-green hues, this deep image shows tantalizing details of the Helix, including its bright inner region about 3 light-years across. The white dot at the Helix's center is this Planetary Nebula's hot, dying central star . A simple looking nebula at first glance, the Helix is now understood to have a surprisingly complex geometry .