What do you call a contracting cloud of gas and dust with enough mass to form a star?

A contracting cloud of gas and dust with enough mass to form a star is referred to as a protostar. This stage is crucial in the life cycle of a star, as it signifies the initial phase where gravitational forces pull together the material in the cloud, causing it to collapse and begin heating up. As the core temperature rises, nuclear fusion may eventually commence, leading to the formation of a fully developed star.

In contrast, a black hole is the endpoint of a massive star's life, where gravitational collapse has occurred to the extent that not even light can escape its pull. A supernova is an explosive event that marks the death of a massive star, resulting from the core collapse or the rapid nuclear reactions that occur when the star depletes its nuclear fuel. A galaxy is a vast collection of stars, gas, dust, and dark matter held together by gravitational forces, and does not represent the stage of an individual star's formation. The definition of a protostar directly relates to the processes involved in star formation and sets the foundation for subsequent stellar development.