thumb|upright=1.2|left|Schematic of stellar evolution Stellar evolution starts with the gravitational collapse of a giant molecular cloud. Typical giant molecular clouds are roughly across and contain up to . As it collapses, a giant molecular cloud breaks into smaller and smaller pieces. In each of these fragments, the collapsing gas releases gravitational potential energy as heat. As its temperature and pressure increase, a fragment condenses into a rotating ball of superhot gas known as a protostar. Filamentary structures are truly ubiquitous in the molecular cloud. Dense molecular filaments will fragment into gravitationally bound cores, which are the precursors of stars. Continuous accretion of gas, geometrical bending, and magnetic fields may control the detailed fragmentation manner of the filaments. In supercritical filaments, observations have revealed quasi-periodic chains of dense cores with spacing comparable to the filament inner width, and embedded two protostars with gas outflows.
thumb|upright=12|left|Schematic of stellar evolution Stellar evolution starts with the gravitational collapse of a giant molecular cloud Typical giant molecular clouds are roughly across and contain up to  As it collapses a giant molecular cloud breaks into smaller and smaller pieces In each of these fragments the collapsing gas releases gravitational potential energy as heat As its temperature and pressure increase a fragment condenses into a rotating ball of superhot gas known as a protostar Filamentary structures are truly ubiquitous in the molecular cloud Dense molecular filaments will fragment into gravitationally bound cores which are the precursors of stars Continuous accretion of gas geometrical bending and magnetic fields may control the detailed fragmentation manner of the filaments In supercritical filaments observations have revealed quasi-periodic chains of dense cores with spacing comparable to the filament inner width and embedded two protostars with gas outflows