Horsehead and Flame Nebulae

This nebula complex is part of the large star-forming region in Orion. The bright star, the leftmost in Orion’s belt, is Zeta Orionis or Alnitak. It energizes the glowing gas; the red color is from ionized hydrogen. The horsehead, known as B33, is dark material blocking the glow of the ionized gas. The nebula is 1500 light-years from us.