Fox Fur nebula, optical image. This is a large complex of gas and dust containing several hot young stars, which formed within it. Powerful radiation from these stars ionises some of the hydrogen gas in the nebula, causing it to emit red light (an emission nebula). Some of the gas and dust in the nebula does not emit its own light but instead reflects the light from the bright stars. This forms a reflection nebula (lower left). These typically appear blue as blue light is scattered more effectively than red light. Numerous dark bands of cold gas and dust, which do not emit any light, are seen silhouetted against the bright nebulae. The complex lies some 2600 light years from Earth in the constellation Monoceros.