How Did The Star Collapse After The Collapse Of The Interstellar Star?

Protostar
This is the stage in which the star begins to form after the collapse of the interstellar cloud. It happens in small molecular clouds that can be referred to as dense cores. In the beginning the dense core has a level of balance between its own gravitational forces (self-gravity), and both the magnetic pressure, and gas pressure. The self-gravity acts to compress the dense core, while the gas, and magnetic pressures act to inflate it. The core’s self-gravity will eventually overwhelm it as it continues to increase in size, by accruement from the cloud around it. The pressure from its increased mass will trigger the core to collapse. The collapsing will continue as long as there is gravitational binding energy to be eliminated. Eventually
This region becomes known as the First Hydrostatic Core. The collapse is now essentially stopped. The core continues to rise in temperature, according to the virial theorem. The core is further heated by gas falling towards this region that create shockwaves, the core can reach temperatures of temperatures of 2000 – 3000 K. Once the density reaches approximately 10−8 g / cm3, of the material that is infalling, the star has reached a level of transparency that allows energy to be radiated from it. The radiation of energy away from the star’s exterior combined with the convection of energy in the star’s interior allow for it to contract further. The star will continue to contract until the gas within the star is hot enough to create internal pressure inside the star that can support the star’s structure from anymore gravitational collapse. When this happens the stars can be said to be in a state called hydrostatic equilibrium. A star in hydrostatic equilibrium has reached temperatures high enough for nuclear fusion of hydrogen to happen. For a more-massive protostar, the core temperature will reach 10 million kelvin at some stage, initiating the proton–proton chain reaction and allowing hydrogen to fuse, first to deuterium and then to helium. In stars of slightly over 1 M☉, the carbon–nitrogen–oxygen fusion
This is theorised as how the excess angular momentum of the infalling material is expelled, allowing the star to continue along its lifecycle, and formation. When surrounding gas, dust, and other material disperse away from the star it can be considered a pre-main sequence star. The path it enters on the H-R diagram, is known as the Hayashi track, this track is characterised as when rapid contraction ends, and become more normalized, while the luminosity of the star which is to begin with very high begins to decrease, though the surface temperature experiences little to know change. Once its reaches the Hayashi limit, it will switch to the Kelvin–Helmholtz timescale. This is characterized as a stage when the pressure drops causing the star to shrink, which causes the core to increase in