Photo Agency - Astronomy - Space - Nature

> Planetary nebula Helix (NGC 7293)

Planetary nebula Helix (NGC 7293)

author: Anglo-Australian Observatory/David Malin Images/Novapix

reference: a-nep72-93010

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. The greenish middle portion is evidence of excited oxygen atoms, while the outer red is predominantly light from nitrogen and hydrogen. The smallest of the radial blobs inside the red shell are about 150 astronomical units across (150 times the Earth-Sun distance) and they 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.

Keywords for this photo:

AAO - AQUARIUS - ASTRONOMY - DWARF - DYING STAR - EVOLUTION - HELIX - NEBULA - NGC 7293 - PLANETARY NEBULA - POSTER - SIDING SPRING - STAR - WHITE DWARF -