Scientists figured out that atoms of one type of element could be transformed into atoms of a different element. In 1929, George Gamow, an American physicist who came from Russia, suggested that four hydrogen nuclei fused together to form one helium nucleus called hydrogen fusion. Not many details were known about fusion at this point. It was not until the 1950 s that scientists were certain that proton-proton fusion was what fueled the sun. Scientists today study the sun in many ways, one in which is by studying the Standard Solar Model .
Sunspots are relatively cool areas that appear as dark blemishes on the face of the sun.
The sun is a huge ball of hot gas. It is glowing brightly because it is so hot. The gas is made of atoms of hydrogen and other chemical elements. The sun is so hot that sometimes pieces are shot out into space. These pieces are single atoms or parts of atoms.