Getty Images
Horsehead nebula, optical image.
The horsehead shape is caused by dark nebula Barnard 33 (B 33). This cloud of dust and gas obscures the light from the emission nebula IC 434 that lies behind, seen here as the red region at top. The gas of this nebula glows as it is...
Getty Images
Trifid nebula (M20), optical image.
This nebula is a region of star birth. The red area is an emission nebula, where radiation from hot, newly formed stars ionises the surrounding gas and causes it to glow. The blue area is a reflection nebula, which does not emit light,...
Getty Images
Barred spiral galaxy (NGC 2903), optical image.
This galaxy lies around 25 million light years away in the constellation Leo. It has spiral arms and a central bar, like our own galaxy, the Milky Way. The red areas are regions of star formation. The radiation from hot young stars...
Getty Images
Rosette nebula (NGC 2237), optical image.
This nebula is an emission nebula, known as the Rosette nebula because of its round, flower-like shape. Emission nebulae are clouds of gas and dust that are ionised by radiation from hot stars within them, causing them to glow. At the...
Getty Images
Emission nebula (NGC 6559), optical image.
Emission nebulae are clouds of gas and dust that are ionised by radiation from hot stars within them, causing them to glow red. Around the bright stars are regions of reflection nebulosity, where fine dust particles reflect the light of...
Getty Images
Snake nebula (Barnard 72), optical image.
The Snake nebula, seen at centre, is so-called because of its curved S-shape. It is formed of a region of dust clouds that obscure the light from the stars behind, creating a dark silhouette. This nebula, part of the larger Dark Horse...
Getty Images
Emission nebula (NGC 6357), optical image.
Emission nebulae are clouds of gas and dust that are ionised by radiation from hot stars within them, causing them to glow. This nebula lies in the constellation Scorpius. The ionising radiation comes from the open cluster Pismis 24,...