noun
- a contracting mass of gas and dust that represents an early stage in the formation of a star, before nuclear fusion begins
Usage: astronomy
Examples
- The protostar continued to collapse under its own gravity.
- Astronomers observed a protostar forming within the dense molecular cloud.
- It takes millions of years for a protostar to develop into a main sequence star.
- The protostar’s temperature gradually increased as it contracted.
- Scientists used infrared telescopes to study the hidden protostar.
- The protostar will eventually ignite nuclear fusion in its core.