SOLAR SYSTEM

Detailed explanation-1: -What is a protostar and how does it form? A protostar is a young star that has not yet depleted its surrounding molecular gas through gravitational contraction. Additionally, a protostar’s core has not yet become dense and hot enough for hydrogen nuclei to collide and fuse, forming helium nuclei.

Detailed explanation-2: -Fusion: The energy source of stars. The energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. When the core is hot enough, nuclear fusion commences. Fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

Detailed explanation-3: -A protostar is a hot dense cloud of gas that has not yet begun nuclear fusion in its core.

Detailed explanation-4: -Inside the core of a star like the Sun, fusion proceeds via a process called the proton-proton chain. In this multi-step process, six protons fuse together and the product is a helium nucleus and two protons.

Detailed explanation-5: -A protostar that never reaches this mass threshold will remain a hydrogen cloud, unable to put out light or heat in the same massive quantities as a normal star does, remaining dark and cold.