Description: A sunspot is a temporary, cool region, caused by a strong magnetic field in the Sun's photosphere. Sunspots are areas where tubes of magnetic flux emerge from deeper in the Sun. The high magnetic field increases the magnetic pressure in these regions. To stay at the same pressure as their surroundings, the gas and plasma pressure in the sunspot must drop, making it cooler than its surroundings. As they are cooler than the surrounding photosphere, sunspots can be seen through a telescope as dark patches/blotches on the surface of the Sun. Sunspots range in size from tens of kilometers across to over a hundred thousand kilometers across. They can persist for timescales between a few days and a few months. The number and location of sunspots on the Sun varies over the solar cycle. Other stars are also thought to have spots caused by their magnetic fields.

Related Terms:

• Photosphere
• Solar Cycle
• Sun
• Sunspot Cycle
• Magnetic Field

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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