protostar: meaning, definition, pronunciation and examples
C2Technical/Scientific
Quick answer
What does “protostar” mean?
A contracting mass of gas in the early stage of a star's formation, before nuclear fusion begins at its core.
Audio
Pronunciation
Definition
Meaning and Definition
A contracting mass of gas in the early stage of a star's formation, before nuclear fusion begins at its core.
In astronomy, a young stellar object that has not yet reached the main sequence, representing the earliest observable phase of stellar evolution where gravitational collapse heats the core but fusion has not ignited.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or spelling differences. The term is international scientific vocabulary.
Connotations
Identical technical connotations in both varieties.
Frequency
Equally rare outside astrophysical contexts in both regions.
Grammar
How to Use “protostar” in a Sentence
The protostar [verb: collapses/forms/evolves] into a star.Astronomers observed a protostar [prepositional phrase: in the Orion Nebula].Vocabulary
Collocations
Examples
Examples of “protostar” in a Sentence
adjective
British English
- The protostar phase is crucial to understanding stellar masses.
- They studied the protostar winds using radio telescopes.
American English
- The protostar stage is key to understanding stellar masses.
- They studied protostar outflows using radio telescopes.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Exclusively used in astrophysics, astronomy, and related physical science papers and lectures.
Everyday
Extremely rare. Might appear in popular science documentaries or articles.
Technical
The primary domain. Used with precision to describe a specific phase of stellar evolution.
Vocabulary
Synonyms of “protostar”
Neutral
Weak
Vocabulary
Antonyms of “protostar”
Watch out
Common Mistakes When Using “protostar”
- Using 'protostar' to refer to any young star (some young stars are past the protostar phase).
- Pronouncing it as 'pro-toe-star' with equal stress on all syllables.
- Confusing it with 'proto-star' (hyphenated form is less standard).
FAQ
Frequently Asked Questions
Not in the common sense. It is a stellar object in formation. It becomes a true star only when the core temperature and pressure are sufficient to sustain nuclear fusion.
The duration varies with mass. For a star like our Sun, the main protostar phase lasts about 100,000 to a few million years.
Almost never. They are often hidden within dense clouds of gas and dust (nebulas) and emit most of their energy in infrared wavelengths, requiring powerful telescopes.
A protostar has the potential to become a star by igniting fusion. A brown dwarf is an object that forms like a star but never accumulates enough mass to sustain core hydrogen fusion; it is a 'failed star'.
A contracting mass of gas in the early stage of a star's formation, before nuclear fusion begins at its core.
Protostar is usually technical/scientific in register.
Protostar: in British English it is pronounced /ˈprəʊ.təʊ.stɑː/, and in American English it is pronounced /ˈproʊ.t̬oʊ.stɑːr/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
PROTO = first, STAR = star. A 'first-star' or earliest version of a star.
Conceptual Metaphor
A COCOON or EMBRYO (for a star); a SEED before it becomes a full-grown plant.
Practice
Quiz
What is the primary energy source of a protostar?