Our Sun is a star. It emits its own light. Its mass is 1.99×10 ³º Kg. Sun is actually a sphere of gases. In its core, hydrogen atoms keep moving on a high speed. The temperature of sun is around 6000º C. Due to this high temperature, these hydrogen nuclei often strike to each other.
Whenever it happens, helium atom along with a large amount of energy is produced. It is the energy which we get from sun. The whole process is called nuclear fusion. It can be represented as:
4H → He + Energy
So when four hydrogen nuclei collide, one helium nucleus and a big amount of energy is produced. This conversion of hydrogen nuclei into helium nuclei takes place in some other ways also. During this change, some mass of sun gets destroyed. As a result of this, our sun is slowly dying.
Now, Solar energy is also very complicated. We receive sun energy in three types of waves. These are: Ultra violet rays, Visible rays, Infra red rays All these rays have different wavelength and different effects.
Sun’s ultra violet rays have shortest wavelength. These are also invisible rays. Ultra violet rays are responsible for change in skin color due to sun light. Too much ultra violet rays may also cause skin cancer.
Second component, visible light, as name suggests, is only visible part of sun light. It consists of VIBGYOR. Its wavelength is in the range of 400 nanometer to 700 nanometer.
Third, Infrared rays are of longest wavelength. These are also invisible just like ultra violet rays. These rays are capable to produce heating effect. These rays are the mother of heating sensation.
Sun is also the center of our solar system. Our solar system consists of sun, planets, satellites, asteroids, comets, meteors etc. It is the gravitational force of sun which keeps all the members of our solar system in their accurate places.
We can consider sun as father, the head of the family, which has full control over his children (planets). All planets depend upon sun for light .These always keep revolving around the sun from west to east.
Sun is also the major source of energy. Almost all types of energies present in world come directly or indirectly from sun. Wind energy, water energy, biomass energy, geothermal energy, tidal energy etc all are produced from sun.
In nut shell, sun is the major part of our universe. It is difficult to think life without sun.