ScienceAugust 29, 2026

arcseconds

ARK-sek-uhndz

Definition

A unit of angular measurement equal to 1/3600th of a degree, used here to describe the precise size of the area of sky that a telescope's pixels can sample.

Etymology

Derived from 'arc' (from Latin arcus, meaning 'bow' or 'curve') and 'second' (from the Latin pars minuta secunda, meaning 'second diminished part,' reflecting its role as a second subdivision of a degree after the minute).

In the news

The article uses arcseconds to quantify the field of view of various camera channels, helping to calculate exactly how much larger the Roman telescope's coverage is compared to Hubble's.

NASA’s Roman Space Telescope is scheduled to launch tomorrow, August 30, carrying a mirror the same 2.4-metre diameter as Hubble’s. Yet its main camera will capture at least 100 times more sky in each exposure—surveying in one shot what Hubble woul

Read the full article ↗

ScienceBlog.com

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