Protostar Formation

Protostar formation begins within a cold, dense cloud of gas and dust in space. Gravity causes parts of this cloud to collapse, increasing pressure and temperature in the core. As material continues to gather, the core heats up but hasn't yet started nuclear fusion—the process that powers stars. This stage, called a protostar, is characterized by being bright in infrared light due to the heat released during collapse. Eventually, when the core becomes hot enough (around 10 million degrees Celsius), nuclear fusion starts, and the protostar transitions into a main-sequence star, capable of shining steadily for millions or billions of years.