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.

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.

The Sun is average star, but without its energy we would not exist.

Elizabeth Brown (1830 – 1899)

The Sun is average star, but without its energy we would not exist.

An eclipse of the Sun, or Solar Eclipse, occurs when the Moon comes directly between the Sun and the Earth so that the Earth lies in the shadow of the Moon.

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.