prestars
Prestars are dense, cold condensations within molecular clouds that represent an early stage in star formation. They are gravitationally bound objects that have not yet formed a central protostar and therefore lack significant internal energy output. Typical prestellar cores have temperatures around 8–12 K and hydrogen molecule densities of 10^4–10^5 cm^-3. They are primarily identified by their faint or absent infrared emission and by submillimeter dust continuum radiation, as well as by molecular line tracers such as N2H+ and NH3 that indicate high density and low turbulence.
Formation and evolution: Prestars arise through the fragmentation and contraction of larger cloud structures under gravity,
Observational significance: Studying prestars informs theories of core formation, the initial mass function, and the timescales