Stars like the Sun start their lives as cold,dense cores of dust and gas that collapse under the influence of gravity until nuclear fusion is ignited. These cores contain hundreds to thousands of solar-masses of fabric and have gas densities about a thousand times greater than typical interstellar regions (the typical value is about one molecule per cubic centimeter). How the collapse process occurs in these embryos in poorly understood, from the number of stars that form to the factors that determine their final masses, or as well as the detailed timescale for stellar birth. fabric,for example, might simply descend freely to the center of the core, or but in most realistic scenarios the infall is inhibited by pressure from warm gas,turbulent motions, magnetic fields, and some combination of them.
Source: phys.org