Formation of a Protostar

We learned in my previous post that in a nebula a very cold gaseous cloud collapses due to gravity. The particles rush towards the core of the cloud and due to the collapsing the frequency of collision among the particles increases so does the thermal energy at the core. The gravity keeps pushing on the core to get smaller and smaller. Smaller the core faster it has to spin (this is called the conservation of angular momentum). Due to the spinning the cloud start to takes the shape of a disc. Below is the rotating disc of a protostar.   

A star can take million of years to reach this stage. Some protostars spin so fast that hot gases start to flow outwards making the Jet streams. Spinning protostar with a Jet shown below;  

Some protostars spin so fast that they split to form binary stars. Please note, gravity is responsible for the contraction of the star. Now two forces working against the gravity to expand the star; first one is thermal (heat) energy produced due to collision of particles and the angular momentum because of the spinning of the disc. But gravity still winning and keep contracting the star until the temperature of the core becomes sufficient enough to trigger the fusion of hydrogen.  Next post we will learn about nuclear reactions and fusion is one of them. 

Stay tuned……………….more star story to come!!