Alnitak, part of the Orion Belt in the constellation Orion, is surrounded by several prominent nebulas that are part of the Orion Molecular Cloud Complex, a massive star-forming region approximately 1,350 light-years from Earth. These nebulas include:  

Located near Alnitak, the Flame Nebula (NGC 2024) is a bright emission nebula.  The ultraviolet radiation from Alnitak ionizes hydrogen gas, causing it to emit light.  Dark dust lanes cross its bright central region, creating a fiery appearance.  

IC 434 is the bright emission nebula that serves as the backdrop for the Horsehead Nebula.  Its reddish glow is due to hydrogen gas being excited by the radiation from nearby stars, including Alnitak.  

Situated to the right (in this image) Alnitak, the Horsehead Nebula (Barnard 33) is a dark nebula.   It is a cloud of dust and gas that appears silhouetted against the bright emission nebula IC 434 that lies behind it.

Located near the Horsehead Nebula, is the bright reflection nebula NGC 2023.  It is illuminated by the star HD 37903 and is one of the brightest reflection nebulas in the sky.  It features a combination of molecular clouds and photodissociation regions.  

These nebulas are intricately linked, forming part of the dynamic and visually stunning Orion Molecular Cloud Complex.