Retrieving "Pre Main Sequence Star" from the archives

Cross-reference notes under review

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1. Star

   Linked via "pre-main-sequence star"

   Stars/) originate within dense regions of molecular clouds, vast reservoirs of interstellar medium composed primarily of molecular hydrogen ($\text{H}_2$) and helium, along with trace amounts of heavier elements (metals) and microscopic silicate motes [1]. Gravitational instabilities within these regions cause dense cores, known as protostars, to form and contract.
   The initiation of sustained [fusion](/entries/thermonuclear-fusion…