The Horsehead nebula (also known as Barnard 33) is an extension of
another large dark nebula made of gas and dust. It blocks the
background light from stars located in our own Galaxy, as well as the light from distant galaxies (the small ellipses on the image).
Behind "The Horsehead" lies another nebula, that is seen in emission, IC 434.
It appears on this image as the cloudy structure behind "The Horsehead".
Barnard 33 is part of the Orion molecular cloud, a large high-mass
star formation complex that includes the great Orion Nebula (Messier 42). It is distant
of about 1,500 light years from us. The field on this image extends over
8 light years.
Technical description: This image was taken with the CFH12K Camera installed at the telescope prime focus. This color composite image was made from a 9 minute V exposure (wavelength = 550nm) and a 20 minute I exposure (wavelength = 814nm).