Planetary nebula Helix in Aquarius
author: Anglo-Australian Observatory/David Malin Images/Novapix
reference: a-nep72-93006
Image Size 300 DPI: 51 * 40 cm
This faint object is the nearest planetary nebula to the Sun and on deep photographs has a diameter of about half a degree -- the same apparent size as the Sun in the sky. The AAT colour picture shows the brighter parts of the nebula, revealing various ionisation levels within the shell of matter ejected from the central star. This picture was made without unsharp masking. Unsharp masking emphasises the smallest of the radial blobs inside the red shell, which are about 150 astronomical units across (150 times the Earth-Sun distance). These radial streaks give this beautiful object its alternative name, the Sunflower Nebula. The Helix is about 400 light years away, or about 100 times more distant than the nearest stars.