Unknow facts about Sun

The sun is the star at the center of the solar system 

The Sun is the primary source of energy for Earth's climate system 

It has the mass of about , Earths and is about times the diameter of the Earth. 

The Sun is thought to be about.  billion years old. 

The Sun's core has a very high temperature, more than    million degrees Kelvin 

The sun is officially classified as a yellow dwarf star  

The element helium got its name from the Sun. 

The mass of the Sun is 500 times greater than the sum of the masses of all the planets around it. 

The photosphere is the layer of the Sun's surface that emits visible light. 

The Sun's activity changes periodically.