The Horsehead Nebula in Orion

on the INT Wide-Field Camera

The nebulosity in this region is just a part of a much larger cloud that covers most of the constellation of Orion. The red area in the top of the picture is Halpha emission caused by UV light from Sigma Orionis exciting the gas. The small blueish region near the bottom left is a reflection nebula, in which light from the embedded star is scattered by dust.

The picture was produced by composing three, two-minute, exposures taken through R, V and B Harris photometric filters, approximating the normal red, green and blue passbands. The area shown is from a single chip of the 4-chip Wide-Field Camera ccd mosaic at the prime-focus of the 2.54m Isaac Newton Telescope.

North is at the left of the picture; it is presented in this orientation as per normal to present the `Horse's Head'.

psb@ast.cam.ac.uk