Phenomena: sunspots

• Charateristics:• These are dark areas on the Sun’s surface; the are

cooler than the brightly lighted part of the sun’s surface• Sunspots are due to magnetic fields near them which

reduce the rate at which heat escapes from the core• They are of different sizes• They usually exist in pairs or in groups• They last from several hours to several weeks• They appears to move across the sun’s surface because

the sun is rotating from west to east.

Phenomena: prominences

• A prominence is an explosion of burning hydrogen & helium from sun’s surface

• Each exploding cloud of hot gases appears bright red and is curved

• The hot gases may rise to a height of 100 000 km and reach a temperature of 10 000 o C

• The hot gases will cool down and will be pulled back to the sun by the sun’s gravitational force

• Some charged particles and rays from the escape into outer space, forming solar wind

• Solar winds cause the tail of a commet to point away from the sun.

Phenomena : solar flares

• Solar flares are bursts of light from the sun’ssurface

• They usually occur near the sunspots• Each flares lasts from several minutes to

several hours• Solar flares release charged particles and rays

into outer space; some of these particles and rays reach the earth.