What is yso?

YSO stands for Young Stellar Object, which is a term used to describe a newly formed star or a star that is still in the process of forming. Young Stellar Objects are typically classified as either protostars or pre-main-sequence stars. Protostars are surrounded by a dense cloud of gas and dust, which is slowly being pulled in by the star's gravity. As the protostar accumulates more matter, its temperature and pressure increase, eventually reaching a point where nuclear fusion begins at its core, marking the birth of a new star. Pre-main-sequence stars, on the other hand, are still undergoing gravitational contraction and have yet to reach the temperature and pressure required for nuclear fusion to occur at their cores. YSOs are important objects to study since they provide insights into the early stages of star formation and the physical processes that shape the environments where stars are born.