vertical circle

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vertical circle

A vertical circle is drawn on a diagram of the celestial sphere.

Definition

Noun: 1. A great circle on the celestial sphere passing through the zenith and perpendicular to the horizon: In astronomy and navigation, a vertical circle is an imaginary large circle on the sky that runs from the zenith (the point directly overhead) down to the horizon, passing through a specific celestial body or point. It is always perpendicular to the horizon.

Usage

The term vertical circle is a technical term used primarily in astronomy, celestial navigation, and surveying to describe a specific reference circle for locating objects in the sky. * It is used to measure the altitude (angular height above the horizon) of a star or planet. * The prime vertical circle is a special case that passes through the east and west points on the horizon.

Examples
  • Noun:
    • The astronomer calculated the star's position by noting its intersection with the vertical circle.
    • The sextant measurement is referenced to a vertical circle to determine latitude.
    • The prime vertical circle is an important reference in the horizontal coordinate system.
Advanced Usage
  • Prime Vertical Circle: The specific vertical circle that passes through the east and west points of the horizon, as well as the zenith and nadir. It is perpendicular to the observer's meridian.
    • The sun crosses the prime vertical circle at sunrise and sunset during the equinoxes.
Variants and Related Words
  • Altitude Circle: A synonym for a vertical circle, emphasizing its use in measuring altitude.
  • Azimuth Circle: A related concept; while a vertical circle measures altitude, an azimuth circle is a circle of constant azimuth (compass direction) on the celestial sphere.
  • Great Circle: A circle on a sphere whose center is the center of the sphere. A vertical circle is a type of great circle.
Synonyms
  • Altitude circle
  • Circle of altitude
Related Concepts (Not Phrasal Verbs or Idioms)
  • Celestial Sphere: The imaginary sphere surrounding Earth onto which all celestial objects are projected.
  • Zenith: The point in the sky directly above an observer.
  • Horizon: The line where the earth seems to meet the sky.
  • Meridian: The great circle passing through the celestial poles and the observer's zenith.
vertical circle

A vertical circle is drawn on a diagram of the celestial sphere.

Noun
  1. a great circle on the celestial sphere passing through the zenith and perpendicular to the horizon