arcminute
Học thuậtThân thiện
Definition
Noun: - A unit of angular measurement equal to one sixtieth (1/60) of one degree. It is used in astronomy, navigation, and geometry to measure very small angles.
Usage
- The term "arcminute" is used in precise scientific and technical contexts to specify small angular distances or sizes. It is often represented by the prime symbol (′). For example, 30 arcminutes is written as 30′.
- It is commonly used to describe the apparent size of celestial objects, the resolution of telescopes, or the accuracy of directional measurements.
Examples
- The apparent diameter of the full Moon is about 30 arcminutes.
- The star's position was measured with an accuracy of less than one arcminute.
- This telescope has a resolution of 5 arcminutes, meaning it can distinguish two points separated by that angle.
Advanced Usage
- Arcminutes in Astronomy: Often used alongside its subdivision, the arcsecond (1/60 of an arcminute). A full circle is 360 degrees, 21,600 arcminutes (360 × 60), or 1,296,000 arcseconds.
- Nautical and Cartographic Use: Used in navigation charts and for expressing latitude and longitude with high precision (e.g., 45° 30′ N).
Variants and Related Words
- Minute of arc: A synonymous term for arcminute.
- Arcsecond (noun): A unit of angular measurement equal to 1/60 of an arcminute (1/3600 of a degree).
- Degree (noun): A larger unit of angular measurement; there are 60 arcminutes in one degree.
Synonyms
- Minute of arc
- Minute (in technical contexts, when the prime symbol ′ is used)
Notes
- The term "arcminute" is specific to angular measurement. It should not be confused with the unit of time (minute), even though both are subdivisions of a larger unit (degree and hour, respectively) into 60 parts.
- In casual or non-technical language, the word "minute" alone is almost never used to mean "arcminute"; the full term "arcminute" or the prime symbol is necessary for clarity.
Noun
- a unit of angular distance equal to a 60th of a degree