Sunspots are cooler than the surrounding gas in the photosphere because sunspots are cooler than the surrounding gas in the photosphere because magnetic fields lift material from the sunspot and quickly cool the material. there is less fusion occurring there. they are regions where convection carries cooler material downward. magnetic fields trap ionized gases that absorb light. strong magnetic fields slow convection and prevent hot plasma from entering the region

The presence of strong magnetic fields results in the slow convection and also prevents the movement of hot plasma from entering the region

Explanation:

The photosphere refers to the visible surface of the sun, whereas the sunspots are the small dark spots that occur on the surface of the sun. These sunspots are comparatively cooler than the other gases that are present in the photosphere. It is because of the presence of the strong magnetic field, that lowers the surface temperature and reduces the effects of convection process and does not allow the movement of hot plasma into the region.

Due to this obstruction in the release of heat in the sun's surface, the sunspots are cooler than the surrounding gases.