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primary mirror

British  

noun

  1. the mirror that collects and focuses the incoming light in a reflecting telescope

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

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By combining the four VLT 8.2-metre telescopes at ESO's Paranal Observatory, they can resolve details as if astronomers would employ a telescope with a primary mirror of 200 metres in diameter.

From Science Daily • Jan. 8, 2024

Combined with the telescope's 6.5m-wide primary mirror and associated optics it takes astonishing pictures.

From BBC • Aug. 31, 2023

By blocking much of the starlight, we transformed the primary mirror into an array of small collectors, allowing Keck to work much like modern radio telescopes that link many smaller antennas together.

From Scientific American • Aug. 18, 2023

With its infrared detectors and a booming primary mirror 21 feet wide, it is ideal for investigating the early years of the universe.

From New York Times • Apr. 29, 2023

The primary mirror in this telescope is 39.3 meters across.

From Textbooks • Oct. 13, 2016