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MCQIntermediateGalaxies & Extragalactic Astronomy
BAAO — 2022 Astronomy & Astrophysics Challenge
Question 4
The Gaia spacecraft, launched in 2013, is designed to map the sky with unprecedented precision. Its third data release (from June 2022) had 1.8 × 10⁹ objects detected of which 1.9 × 10⁶ were highly likely to be quasars (distant galaxies with an actively feeding black hole responsible for their light output). Assuming the quasars are evenly distributed across the whole sky, what is the approximate average angular separation between them?
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Source
Source: British Astronomy and Astrophysics Olympiad (BAAO), Astronomy & Astrophysics Challenge 2022. Question text, answer-choice text, and answer were transcribed from the official BAAO paper and solutions PDFs; the explanation and metadata are original.