Why sunspots are cooler than surrounding areas on the sun's surface?
The strong magnetic field suppresses the release of heat into the photosphere making sunspots cooler than their surroundings. Because they are much cooler than the surrounding photosphere sunspots appear darker even though they are still many 1000s of degrees Celsius.
All in all, the sunspots appear dark because the are darker than the surrounding surface. They're darker because they are cooler, and they're cooler because of the intense magnetic fields in them.
- Sunspots come in pairs with opposite magnetic polarity. If we could bury a giant horseshoe magnet beneath the surface of the Sun, it would produce a magnetic field similar to that generated by a sunspot pair.
- Many sunspots, like the ones shown in the image on this page, are as large as Earth! Most spots range in size from about 1,500 km (932 miles) to around 50,000 km (31,068 miles) in diameter. Once in a while, huge sunspots the size of Jupiter show up on the Sun's surface.
- The Sun is always sending out a stream of electrically charged particles called the solar wind. When the particles get close to Earth, they start to feel the effect of Earth's strong magnetic field.
Sunspots are darker, cooler areas on the surface of the sun in a region called the photosphere. The photosphere has a temperature of 5,800 degrees Kelvin. Sunspots have temperatures of about 3,800 degrees K. They look dark only in comparison with the brighter and hotter regions of the photosphere around them.
- The magnetic fields in each individual sunspot either point into or out of the sun, with a single magnetic polarity, but sunspots usually travel in connected pairs. Sunspots are linked by magnetic loops that extend upward into the overlying, and transparent, solar atmosphere.
- Sunspots are storms on the sun's surface that are marked by intense magnetic activity and play host to solar flares and hot gassy ejections from the sun's corona. It emanates from the sun and influences galactic rays that may in turn affect atmospheric phenomena on Earth, such as cloud cover.
- The Sun is 864,400 miles (1,391,000 kilometers) across. This is about 109 times the diameter of Earth. The Sun weighs about 333,000 times as much as Earth. It is so large that about 1,300,000 planet Earths can fit inside of it.
Sunspots are caused by the Sun's magnetic field welling up to the photosphere, the Sun's visible "surface". The powerful magnetic fields around sunspots produce active regions on the Sun, which often lead to solar flares and Coronal Mass Ejections (CMEs). Our Sun isn't the only star with spots.
- Sunspots are caused by the Sun's magnetic field welling up to the photosphere, the Sun's visible "surface". The powerful magnetic fields around sunspots produce active regions on the Sun, which often lead to solar flares and Coronal Mass Ejections (CMEs). Our Sun isn't the only star with spots.
- Some changes in your skin come with age, such as the unpopular age spots (also known as sun spots or liver spots). These have nothing to do with the liver and are caused instead by long-term sun exposure. Some of these dark spots, however, may look suspiciously like melanoma, the most deadly form of skin cancer.
- Sunspots have two parts: the central umbra, which is the darkest part, where the magnetic field is approximately vertical (normal to the Sun's surface) and the surrounding penumbra, which is lighter, where the magnetic field is more inclined.
Updated: 3rd December 2019