periastron: meaning, definition, pronunciation and examples
Very LowTechnical / Scientific
Quick answer
What does “periastron” mean?
The point in the orbit of a celestial body where it is closest to the star it is orbiting.
Audio
Pronunciation
Definition
Meaning and Definition
The point in the orbit of a celestial body where it is closest to the star it is orbiting.
The point of minimum distance between two celestial bodies in a binary or multiple star system; more broadly, the closest approach in any orbital system.
Dialectal Variation
British vs American Usage
Differences
No differences in meaning or usage. Spelling and pronunciation are identical.
Connotations
Purely scientific term with no cultural or regional connotations.
Frequency
Extremely rare in both regions, confined to specialised academic and research contexts.
Grammar
How to Use “periastron” in a Sentence
[The/its] periastron [occurs/passes/is] [at a distance/time][To calculate/observe] the periastron [of a binary system]Vocabulary
Collocations
Examples
Examples of “periastron” in a Sentence
adjective
British English
- The periastron passage was observed by the telescope array.
- They calculated the periastron distance with high precision.
American English
- The periastron phase of the orbit is critical for data collection.
- A periastron event triggers increased stellar activity.
Usage
Meaning in Context
Business
Not used.
Academic
Used in astronomy, astrophysics, and orbital mechanics papers and textbooks.
Everyday
Never used in everyday conversation.
Technical
Core term in technical descriptions of binary star orbits, exoplanet detection, and celestial mechanics.
Vocabulary
Synonyms of “periastron”
Strong
Neutral
Weak
Vocabulary
Antonyms of “periastron”
Watch out
Common Mistakes When Using “periastron”
- Misspelling as 'perastron' or 'periastrum'.
- Using it for orbits around planets (incorrect; the correct term would be 'pericentre' or 'periapsis').
- Pronouncing it with stress on the first syllable (/ˈpɛriˌæstrən/). Correct stress is on 'as'.
FAQ
Frequently Asked Questions
Perihelion refers specifically to the closest point to the Sun in an orbit within our Solar System. Periastron is the general term for the closest point to any star.
No, it is a highly specialised scientific term used almost exclusively in astronomy and astrophysics. It is never encountered in general English.
No. For a moon orbiting a planet, the correct term is 'pericentre' or 'periapsis'. 'Periastron' is reserved for orbits where the primary body is a star.
It is determined through precise orbital mechanics calculations, using observations of the orbiting body's position and velocity to model its elliptical path around the star.
The point in the orbit of a celestial body where it is closest to the star it is orbiting.
Periastron is usually technical / scientific in register.
Periastron: in British English it is pronounced /ˌpɛrɪˈæstrən/, and in American English it is pronounced /ˌpɛriˈæstrən/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think 'PERI' (as in perimeter, meaning 'around') + 'ASTRON' (as in astronomy/star). It's the point around the star where the object is closest. The 'i' in periastron can remind you of 'I am close'.
Conceptual Metaphor
NA
Practice
Quiz
What is the antonym of 'periastron'?