# HII Regions

If the star ionizing an HII region suddenly doubled the radiation emitted, would that increase or decrease the temperature? I feel like the expansion of the region would cancel out the increased energy, but I don't know.

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hellfire
Knowing the temperature, the recombination rate $\beta$ is known which provides the necessary information to calculate the radius of the Strömgren sphere. Putting things together you should come to an relation between the radius and the increase in radiation. This would be a nice exercise.