A sunspot is a temporary, dark area on the surface of the Sun that appears cooler than its surroundings. These spots are caused by magnetic activity that inhibits the flow of hot plasma, resulting in lower temperatures. Sunspots can vary in size and can last from days to months. Sunspots are often associated with solar activity, including solar flares and coronal mass ejections. The number of sunspots fluctuates in an approximately 11-year cycle, known as the solar cycle. Scientists study sunspots to better understand the Sun's behavior and its impact on space weather.