Definition

1. Noun:
   • The branch of astronomy that deals with the measurement of the positions and motions of celestial bodies: Astrometry is the precise science of measuring where stars and other objects in space are located and how they move.

Usage

• Astrometry is a fundamental field of astronomy. It provides the data for creating star catalogs and understanding stellar dynamics.
• It is used with verbs like use, apply, study, and advance.

Examples

• Noun:
  • The Gaia spacecraft is revolutionizing astrometry by mapping the positions of over a billion stars.
  • Accurate astrometry is essential for spacecraft navigation through the solar system.
  • His research in astrometry focused on the proper motion of nearby stars.

Advanced Usage

• "High-precision astrometry": Refers to measurements of extreme accuracy, often needed for detecting very small motions like those caused by orbiting planets.
• "Astrometric data": The numerical results or measurements obtained from astrometric observations.

Variants and Related Words

• Astrometric (adjective): Relating to astrometry.
• Astrometer (noun): An instrument for measuring the positions of celestial bodies. (Note: This term is less common than "astrometric instrument".)

Synonyms

• Positional astronomy: A near-synonym emphasizing the measurement of positions.
• Celestial measurement: A more general descriptive phrase.

Related Phrases

• "Astrometric binary": A binary star system detected through the wobble in the observed position of one star, rather than by changes in brightness.

Noun

1. the branch of astronomy that deals with the measurement of the position and motion of celestial bodies