I don't understand why antimatter stars would emit more gamma rays than normal matter. The only difference is the charge right? Then mass and energy should be t

I don't understand why antimatter stars would emit more gamma rays than normal matter. The only difference is the charge right? Then mass and energy should be the same. That is why matter and anti-matter annihilate each other completely because neither has more energy/mass than the other, just opposite charge. And if your are referring to galactic collisions between matter and antimatter galaxies most galactic collisions do not result in star collisions because of the vast spaces in between stars within galaxies. But I could imagine gas clouds from the two opposing galaxies could come into contact and turn matter into gamma emissions.