Hour Angle (Noun)
Meaning 1
(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day.
Classification
Nouns denoting two and three dimensional shapes.
Examples
- The hour angle of a celestial object changes as the Earth rotates from west to east, causing it to appear to rise in the east and set in the west.
- To calculate the altitude of a celestial object, you need to know its declination and hour angle relative to the observer's location.
- The hour angle is used in conjunction with the declination to determine the position of a celestial object in the sky.
- By knowing the hour angle and declination of a celestial object, astronomers can calculate its altitude and azimuth for any given time and location.
- The hour angle of a celestial object is used to determine its position relative to the observer's meridian, which passes through the observer's location and is perpendicular to the horizon.
Synonyms
Meaning 2
The angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial body.
Classification
Nouns denoting spatial position.
Examples
- The hour angle of a celestial body is used in astronomy to determine its position in the sky relative to the observer's location.
- To calculate the altitude of a celestial body, one must first determine its hour angle and declination.
- The hour angle of a star changes as the Earth rotates, causing the star to appear to rise and set in the sky.
- By knowing the hour angle and declination of a celestial body, astronomers can pinpoint its exact location in the sky.
- The hour angle of a planet is used in conjunction with its declination to determine its position in the celestial sphere.