The bright star Alnitak (ζ Ori), the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there.
The bright star Alnitak (ζ Ori), positioned at the start of the Belt of Orion, emits powerful ultraviolet radiation that removes electrons from the large clouds of hydrogen gas present in its vicinity.