angular diameter

American  

noun

Astronomy.

1. the angle that the apparent diameter of a celestial object subtends at the eye of the observer.

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Etymology

Origin of angular diameter

First recorded in 1870–75

Example Sentences

The telescope spent 10 days of exposure time staring at a tiny patch of the sky in the Ursa Major constellation, just one-thirteenth of the moon’s angular diameter.

From Scientific American • Jul. 15, 2022

Since we know how rapidly the Moon moves in its orbit around Earth, it is possible to calculate the angular diameter of the star.

From Textbooks • Oct. 13, 2016

Confirm that the angular diameter of the Sun of 1/2° corresponds to a linear diameter of 1.39 million km.

From Textbooks • Oct. 13, 2016

Unfortunately, the Sun is the only star whose angular diameter is easily measured.

From Textbooks • Oct. 13, 2016

It is one-fifteenth the angular diameter of the full Moon as seen from Earth.

From "Cosmos" by Carl Sagan