Sun spots and flares
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A solar flare is an intense burst of radiation coming from the release of magnetic energy associated with sunspots. Flares are our solar system’s largest explosive events. They are seen as bright areas on the sun and last from mere minutes to several hours.
Scientists classify solar flares according to their x-ray brightness. There are 3 categories: X-, M- and C-class. X-class flares are the largest of these events. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Compared to X- and M-class, C-class flares are small with few noticeable consequences on Earth.
Sunspots are regions on the solar surface that appear dark because they are cooler than the surrounding photosphere, typically by about 1500 K (they are still at a temperature of about 4500 K, but this is cool compared to the rest of the photosphere). They are only dark in a relative sense, a sunspot removed from the bright background of the Sun would glow quite brightly.
The largest sunspots observed have had diameters of about 50,000 km, which makes them large enough to be seen with the naked eye. Sunspots often come in groups with as many as 100 in a group, though sunspot groups with more than about 10 are relatively rare. There are well established methods for measuring the number of sunspots.
Sunspots develop and persist for periods ranging from hours to months, and are carried around the surface of the Sun by its rotation. A typical sunspot consists of a dark central region called the umbra and somewhat lighter surrounding region called the penumbra.
Scientists classify solar flares according to their x-ray brightness. There are 3 categories: X-, M- and C-class. X-class flares are the largest of these events. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Compared to X- and M-class, C-class flares are small with few noticeable consequences on Earth.
Sunspots are regions on the solar surface that appear dark because they are cooler than the surrounding photosphere, typically by about 1500 K (they are still at a temperature of about 4500 K, but this is cool compared to the rest of the photosphere). They are only dark in a relative sense, a sunspot removed from the bright background of the Sun would glow quite brightly.
The largest sunspots observed have had diameters of about 50,000 km, which makes them large enough to be seen with the naked eye. Sunspots often come in groups with as many as 100 in a group, though sunspot groups with more than about 10 are relatively rare. There are well established methods for measuring the number of sunspots.
Sunspots develop and persist for periods ranging from hours to months, and are carried around the surface of the Sun by its rotation. A typical sunspot consists of a dark central region called the umbra and somewhat lighter surrounding region called the penumbra.