Stars are born within the clouds of dust and scattered throughout most galaxies. A familiar example of such as a dust cloud is the Orion Nebula. Turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction.
Heavy elements were formed only billions of years after the formation of the star. The density inside of the star is great enough to sustain fusion for extended time periods required to synthesize heavy elements.
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