Our known star sun is a medium size star among nearly one hundred billion (one billion is one hundred crore) stars present in our galaxy milky way. In the universe there are uncountable numbers of stars like sun. Some are thousand & thousand times more larger than sun. Any way sun is the father of our own solar system. We know that father in each family is the main person who controls all activities of the whole family. Similarly sun, present at the center of the solar system not only supply heat & light to us which is essential for the survival of all life forms on Earth but keep all the  nine planets of solar system to revolve around him for its powerful gravity.

Let us discuss some important points about sun:

k Sun sits in the center of solar system.

k Sun’s diameter is 1,390,000 Km, Sun is the largest celestial object of the solar system.

k   The sun comprises about 70% of hydrogen & 28% helium by mass. The solar energy is produced by nuclear fusion reactions.

k   In each second about 700 million tons of hydrogen are converted to about 695 million tons of helium  and 5 million tons of energy released in form of gamma rays.

k   The sun’s magnetic field is very strong.

k   The dark patches on the surface of the sun are known as Sunspots. These are cooler regions of the sun with a temperature of about 40000 C. These spots may be as large as 50,000 Km, in diameter. These are responsible for magnetic activities and can cause geomagnetic storms on Earth.

k   Some time sun emits a stream of low density charged particles. These are mostly electrons & protons. We called this as solar wind. This wind propagates through out the solar system at a speed of 450 Km per second.

k   When moon lies between Earth & sun, it blocks the sun’s light and creates solar eclipse.

k   The outer layer of sun’s surface is called the photosphere that has temperature of 60000 C, whereas in the core of the sun the temperature is about 15 million 0 C.

k   Sun can survive another five billion years. It has enough hydrogen fuel to burn and produce energy. At the end of it’s life it will start to fuse helium in to heavier elements and then turn in to a red giant, which could collapse in to a white dwarf star - the final end product of any star in the universe.