transit instrument: meaning, definition, pronunciation and examples

It is a specialised type of telescope. While it uses optics to view stars, its mount is fixed to rotate only north-south along the meridian, and its design prioritises precise timing and angle measurement over general viewing.

Mostly in museums of science or maritime history, or preserved at historic observatories like Greenwich. Modern electronic versions (automated meridian circles) are used in some specialist astronomical surveys.

It measures the 'transit' or passage of a star across the observer's meridian—an imaginary north-south line in the sky. The event is called a 'meridian transit'.

For fundamental timekeeping and navigation, yes, replaced by atomic clocks, satellites (GPS), and radio telescopes. However, the principle is still used in some automated telescopes for precise astrometry (star position measurement).

A telescope mounted to pivot precisely in the plane of the meridian, used in astronomy and surveying to measure the precise time celestial bodies cross the meridian, and to determine latitude and longitude.

Transit instrument is usually technical, scientific, historical in register.

Transit instrument: in British English it is pronounced /ˈtrænzɪt ˈɪnstrʊmənt/, and in American English it is pronounced /ˈtrænzɪt ˈɪnstrʊmənt/. Tap the audio buttons above to hear it.