by Joel Hruska, ExtremeTech
Stars are thought to form inside giant molecular clouds of gas, sometimes with diameters hundreds of light years across, with a combined mass equivalent to millions of solar masses. As these clouds collapse, they form fragments. Said fragments are thought to contain the mass that will become both the star and its protoplanetary disc, though there are opportunities for interactions with other nearby clouds. If an aged star near a stellar nursery goes supernova, for example, heavier elements created by the core collapse may form part of the new stars. A nearby supernova can even trigger the formation of new stars when its shock wave sharply compresses the molecular gas cloud.