- A contracting mass of gas which represents an early stage in the formation of a star, before nucleosynthesis has begun.More example sentences
- Elongated chains of dust grains like these appear in the early stages of planet formation around a young protostar, according to a microgravity experiment inside a rocket.
- By peering in wavelengths not visible to the naked eye, through the nebula's gas and dust, astronomers can identify very young stars and even protostars - those that are about to light up, once the gases reach a critical density.
- Rotation forces some of the matter to accumulate in a disk rotating around the protostar (s).
More definitions of protostarDefinition of protostar in:
- The US English dictionary