What is a prostar?
There are nine different stages that a star must pass through before being “born.” The first stage is when a nebula collects and makes a mass of gas and dust then it begins to contract under its own gravity. The second stage in the birth of a star is the protostar. During the protostar stage the young star has begun to collapse on itself, but not collapsed enough to go through the nuclear fusion that is required for it to move on to stage 3. During the protostar stage the star is protected and must get up to 15,000,000 centigrade degrees. After that happens the process moves to stage 3.
The prostar is the second stage of a new born star in a nebula. A new star is born because when the nebula contracts, it becomes are dense and hot and this is how a star is born and is on its first stage. The prostar is it second stage and to reach the third stage it hass to be at least 15,000,000 degree celcius.