Sun

Solar Flares

Solar flares are sudden variations in the brightness of a surface region of the Sun. Magnetic energy builds up in the solar atmosphere, above active regions, where sunspots are located. This magnetic energy is suddenly released as radiation across the entire electromagnetic spectrum.


Sunspots

NASA image of sunspots
Sunspots at solar maximum
Credit: NASA/SOHO

The visible surface of the Sun is called the photosphere. Sunspots are darker, cooler regions on the bright, hot photosphere. Whilst the photosphere has a temperature of around 6000°C, sunspots are between 3000°C and 4000°C.


Daytime Shadows

The animation below shows how shadows change during the day in the northern hemisphere. Shadows are created when an object, such as the stick below, blocks out some of the Sun's light. The length of the resulting shadow depends on how low or high the Sun is in the sky.

Try moving your mouse pointer over the time symbols to pause the animation at that particular time.

 


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