celestial point

Thân thiện

A bright star marks the celestial point directly above the ancient observatory.

Definition

1. Noun:
   • A point in the heavens (on the celestial sphere): A celestial point is a specific, defined location or direction in the sky, as projected onto the imaginary celestial sphere surrounding Earth. It is used as a reference in astronomy and navigation.

Usage Examples

• Noun:
  • The North Celestial Pole is a fundamental celestial point used for navigation.
  • Astronomers calculated the position of the new star relative to known celestial points.

Advanced Usage

• As a reference coordinate: In celestial mechanics, a like the vernal equinox is used as the origin for measuring right ascension.
  • The spacecraft's trajectory was plotted from a fixed celestial point.

Variants and Related Words

• Celestial pole (n): Either of the two points in the sky where Earth's axis of rotation, indefinitely extended, intersects the celestial sphere.
• Celestial equator (n): The great circle on the celestial sphere that is in the same plane as Earth's equator.

Synonyms

• Celestial coordinate: A more general term for a set of values that define a position on the celestial sphere.
• Sky point: An informal term for a location in the sky.

Notes on Meaning

• The term is abstract and technical. It does not refer to a physical object like a star, but to a precise conceptual location used for mapping the sky.

Học thuật

Noun

1. a point in the heavens (on the celestial sphere)