Thomas Aquinas, on Job 9:9

“Who maketh Arcturus, and Orion, and Hyades, and the inner parts of the south.”

“He enumerates these marvels beginning with the North Pole and proceeding to the South Pole. So he says, "He made Arcturus." Arcturus is a constellation in the heavens which is called Ursa Maior and has seven bright stars which never set for us but always circle the North Pole. Next comes, "Orion," for Orion is a very clear constellation in the sky because of its size and the bright clarity of its stars which are found in Taurus and Gemini. Next comes, "The Pleiades," which are stars existing on the breast of Taurus, as it is called, and which are also very clear to the naked eye. The text continues, "and the deep constellations of the South." Here we should note that to those who live on the equator, if indeed there are people there, both poles are visible, since their horizon divides the equator at right angles. Thus it is necessary that the horizon should transverse each pole at the equator. So both poles are visible to those living on the equator, as I have said. To those living north of the equator and going towards the North Pole, the North Pole is elevated above the horizon and the South Pole lies hidden in proportion to the distance they live from the equator. So to us who live in the Northern Hemisphere, the South Pole is never visible, and in the same way, the stars near it are hidden from us in direct proportion to the distance which we live from the equator. These are called the deep constellations of the South because they are hidden from us, as though hidden under the horizon.”

Imported from an open dataset — not yet checked against the printed edition.