clock star

clock star

A bright star, usually situated near the celestial equator, whose position and proper motion are very accurately known so that it can be used for the exact determination of time, for the determination of the error of observatory clocks, and for correction of the positional observations of other stars.

clock star

[′kläk ‚stär]
(astronomy)
Any star that is used to measure time; always a bright star, whose right ascension is well known.
References in periodicals archive ?
Leddy nabbed Strawberry Alarm Clock star performers Colm Hayes and Jim-Jim Nugent from FM104 and gave Marty the boot after three years at the helm.
The Rock Around the Clock star had to disguise his face behind a hat and dark glasses to slip past the throng, after performing to more than 5,000 screaming fans at the Gaumont Theatre.