Which constellation is the flame nebula located in?

The flame nebula is a small part of Orion's molecular cloud. On the right side of the image is the famous Horsehead Nebula, which is also a member of this star-forming region.

The red and purple regions in the nebula come from different physical processes. The bright star on the left side of the image is Auriga AE, which is very hot, and its high-energy starlight hits the electrons of hydrogen atoms in the nearby clouds. When this ion captures electrons again and recombines into normal atoms, it is often accompanied by red light. The color of the purple area is a mixture of the above red light and the blue starlight of Auriga AE star reflected by dust. These two colored areas are called "emission nebula" and "reflection nebula" respectively.