Image divided into four tiles. Top row is the Trifid Nebula. A dense star field surrounds a bright, multi-coloured nebula. One region of the nebula is reddish. This is the hydrogen gas that has been excited by the hot massive stars at the centre of the nebula, causing it to be ionised. This structure is also crossed by dark dust lanes, in an X-shape. These are the dark nebula which are silhouetted against the red portion of the nebula. To the lower left are faint hues of blue-green gas. This is the dust that is reflecting light in our direction. Bottom row is the Helix Nebula. It features a central, large ring-like nebula. The inner part of the ring is a blue-green colour and is diffuse, whilst the outer ring region is reddish in hue, much more defined and clumpy. A central small white star, the white dwarf, emits powerful UV radiation which excites the different elements producing different colours. Surrounding the nebula are many stars. Images on the left are of higher resolution
Replies