Which phenomenon is explicitly mentioned as a potential trigger for the gravitational collapse initiating star formation?

Answer

Shockwave from a nearby supernova explosion

The transition from a diffuse cloud to a star requires a trigger, such as the shockwave from a nearby supernova explosion, the gravitational influence of a passing spiral arm, or reaching the critical density threshold known as Jeans instability.

Which phenomenon is explicitly mentioned as a potential trigger for the gravitational collapse initiating star formation?
astronomyOriginstarformationgas