SOLAR SYSTEM

Detailed explanation-1: -When the force of gravity pulling in on the cloud is greater than the strength of internal pressure pushing out, the cloud collapses into a protostar.

Detailed explanation-2: -A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova.

Detailed explanation-3: -As stars form (during the proto-star stage) they are collapsing and heating up. For much of the formation process they give off a considerable part of their emission in the infra-red. Star formation happens best in great (molecular) clouds of gas and dust, which have a lot of dust particles.

Detailed explanation-4: -How is a Protostar Formed? Inside a nebula, there are areas where gravity causes dust and gas to “clump” together. As these “clumps” gather more and more mass their gravitational pull increases, forcing more atoms together. This process is known as accretion, and the result is a protostar.

Detailed explanation-5: -Over time, the hydrogen gas in the nebula is pulled together by gravity and it begins to spin. As the gas spins faster, it heats up and becomes as a protostar.

Detailed explanation-6: -A protostar is a very young star that is still gathering mass from its parent molecular cloud. The protostellar phase is the earliest one in the process of stellar evolution. For a low-mass star (i.e. that of the Sun or lower), it lasts about 500, 000 years.