Many objects in the sky are brightly coloured. Astrophotograpers often add artificial colours on top of (or instead of) the actual colours. Plus, much of what

Many objects in the sky are brightly coloured. Astrophotograpers often add artificial colours on top of (or instead of) the actual colours. Plus, much of what you see from astronomers (although not from this case) is taken in non-optical parts of the electromagnetic spectrum (e.g. radio waves or x-rays), so those pictures are necessarily artificially coloured.