The sun is a star.
it is the nearest star to the earth
The sun is in the centre of the solar system
It is the biggest object in the solar system
It has a large force of the gravity because of it big mass
The force of gravity causes the planet and the asteroids in
The solar system orbit around it
The sun has an atmospgere which can be
divided into three layer
The corona
The chromospheres
The photosphere
The corona
The corona is the outermost layer of the sun’s atmosphere.it is actually a layer of gas
boiled of from the sun
The corona extend for thousands of kilometre into outer space
It is the hottest layer of gas in the sun’s atmosphere, with a temperature about 1 500 000
degree celcius
The corona gines out x ray
The chromospheres
the choromosphere is the layer of gas below the corona
“chromospheres” means a sphere of a colour,so called because of its
reddish-pink colour
This layer of gas is about 500 km thick
Its temperature can rise about 50 000 degree celcius
It can only been seen during the eclipse of sun because it is not bright
The photosphere
The photosphere is the layer of heavy gas which can bee seen from the earth as a bright
lighted sun surface
“photosphere” mean a sphere of light
The photosphere has temperature about 6 000 degree celcius
Its surface appear very rough the gas from the core bubble through it
Solar flares, prominences and sunspot erupts from it surface
~The phenomena occurring on sun surface ~
1) the sunspot
2) the flares
3) the prominences
the sunspot
sunspot are dark area on the surface of the sun
these area are dark and cooler than the other parts of the sun’s
surface
sunspot will appear after several hours or weeks
they are caused by magnetic field which slow down the emission of
heat from the core of the sun
they are of different size and some have diameter of thousand
kilometre
they usually occur in pairs
they appear to move across the sun surface because the sun rotate
from west to east
the flares
solar flares are burst of light from the sun surface
they give out a lot of energy although it is last for several minutes or several hours
they can reach a temperature of 5 000 000 degree celcius
they also released charge particle to outer space, and some of these particle reach the earth
the prominence
prominence are cloud of burning hydrogen helium exploding from the
sun’s surface
these cloud of hot gases appear bright red and curved, and may
reach a height of more than 100 000 kilometre
they can have a temperature of 10 000 degree celcius
the hot gases cool down after sometimes and pulled back to the sun
by the sun’s gravity. At the same times, some gas escape to the
outer space
the gas which escape to the outer space form the solar wind
the solar wind causes the tail of a comet to point away from sun
effects of sunspot, flares and
prominences on the earth
these ray and charge particle influenced the weather and climate on the earth. It is believed
that a large number of sunspot on the sun’s surface can cause disturbing weather condition on
the earth
the electrically charged particles will collidewith the particles in the earth’s atmosphere will
cause radio and television interference
these electrical charge particles are deflected by the earth magnetic field toward the north and
the south pole. These produce green, yellow and red coloured lights in the sky near the pole at
the night. These coloured are called aurorae
Generation of energy by the sun
the sun is the source of energy of the entire solar system
energy is generated by thermonuclear reactions in the core of the
sun where the temperature and the pressure are extremely high
during thermonuclear reactions in the core of the sun, light
hydrogen atoms combine to form heavier helium atoms with the
release of large quantities of heat energy and the light energy.
The temperature reached in this reaction is about 15 000 000 degree
celcius
The energy generated in the reaction is brought from the core to the
surface of the sun by radiation and convection
Most of the energy radiated from the sun is in the form of heat and
light. Only a fraction of the heat and light reaches the earth
When all the hydrogen in the sun is used up, the sun will become a
small quiet object in the outer space
