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

With an angular diameter of about 0.14 degrees Phobos doesn't blot the whole Sun out - but it definitely makes a fair stab at it.

From Scientific American

In the predawn sky, Mercury appears about twice the angular diameter of Uranus, so will look like a tiny half-moon that is 8 arc seconds across in a large telescope.

From Scientific American

Even with clear skies and a good telescope, turbulence smears out details smaller than about 1 arcsecond in angular diameter — good enough to look up at the Hubble telescope, which is similar in size and altitude to spy satellites, and tell that it is a cylinder, but not much else.

From Nature

This makes it easy to estimate the angular diameter of a star, and Betelgeuse is the one which has the greatest angular diameter of all whose distances we know.

From Project Gutenberg