The stars

1. What is a star?

     The star is a large ball with hot gas. There are trillion and trillion stars in our universe. Those stars are all create by stellar nebula and a action call nuclear fusion. All stars will change to diffenent level by the time. For example giant star to red supergiant,red supergiant to supernova.

2.Types of star

     There are four main types of star, Supergiant, Giant, Main Sequnence and White Drawf. Supergiant and Giant is the stars with high brightness and low temperture. Main Sequence star is special because it include different temperture and brightness(from high to low). Lastly the White Drawf star is the stars that with hgh temperture(10,000-15,000 kelvin), low brightness and small size. 

3.H-R Diagram

     The H-R Diagram is a diagram that use to classifed the difference of each star. For example Temperture,Brightness, and Size. those measurement in the diagram are use to classifed the star.

4.Nuclear fusion

     The nuclear fusion is a action of a star. there are two different molecules that inside the star, hydrogen and helium. When two hydrogen change to become one helium. This process is call the nuclear fusion.

5.The life Cycle of a Star

     At the beginning all star are create by Stellar Nebula. After that it change to three different types of stars Sun like star, Huge star, and Giant star. for example let  talk about the the Sun like star, the Sun like star change to the Red Giants, then the Red Giants change to become Plantary Nebula. After that the Plantary Nebula become White Dwarf  and lastly the white dwarf start to change to the Black Dwaf.