What appears as cooler regions on the photosphere?

Sunspots are cooler regions on the photosphere of the Sun, appearing darker than their surrounding areas. They are caused by intense magnetic activity that inhibits convection currents, which in turn leads to reduced surface temperatures. The typical temperature of sunspots is around 3,000 to 4,000 degrees Celsius, which is significantly cooler compared to the surrounding photosphere, which averages about 5,500 degrees Celsius. This temperature difference creates a contrast that makes sunspots visible as dark spots against the brighter backdrop of the photosphere.

Other features like spicules, solar flares, and coronal holes do not have the same characteristic of appearing as cooler areas. Spicules are jet-like structures that are typically hot and dynamic, solar flares are explosive releases of energy that also produce intense heat, and coronal holes are areas in the corona that are also not cooler but rather associated with lower density and temperature plasma. Thus, sunspots are distinctively recognized as the cooler regions on the photosphere due to their physical properties.