- What is a star?
A star is a huge glowing ball of hot gas that held together by gravity. In addition they create large amount of heat and light through nuclear fusion. Stars are made of in a giant clouds of dust and gas called the stellar nebula. Sometimes the part of the cloud gets smaller because gravity.
There are 4 types of stars example main sequence ,white dwarfs are small dense type of stars and dim. A super giants stars are among the most massive stars in our universe.
giants,and main sequence is the stage where a star spends most of its existence. The H-R diagram is graphical tool that astronomers used to organize stars according to their different luminosity, spectral class , colors ,temperature and evolutionary stage. The nuclear fusion is a reaction inside a star change two hydrogen gas molecules into a helium molecule this is how stars makes energy.
