Description
This location just below the hot young star Alnitak at top center, is a hydrogen emission region powered by the star right of center called Sigma Orionis. Sigma Orionis excites hydrogen gas in the region to glow red silhouetting the dark dust feature we call the "horsehead".
To the upper left of Alnitak is another gorgeous emission nebula known as the Flame Nebula. None of these are visible without a telescope or an exceedingly dark sky or both.