This area of sky shows dense regions of stars, so close together that they cannot easily be separated, interspersed with blank regions indicating the presence of dark clouds of gas and dust which obscure the light from the more distant stars. The sky appears blue for a similar reason, although the Sun appears yellow. The nebulae in this poster are very faint and would only be seen as faint smudges even when viewed through a powerful telescope. Their colours were only revealed when photographs such as this became available. They do not therefore have popular names and are only known by their catalogue names.
North is up and East to the left.
The colour picture is produced by sequentially printing the original photographs through the appropriate colour filter onto colour material. Colour film, as used for conventional photography, does not register the colour in objects as faint as these nebulae.