Fortress Monastery

This is the transit of one of the Knights' orbital monasteries. The reason why they're called the Knights of the Sun is because many of these monasteries are inside the orbit of Hearthside very close to Focus. They're located where they are so as to better contemplate the life-giving icon of the Light that is the Hearth Star.

Many research monks who focus [hehe] on solar science are colocated in these monasteries. They aren't directly affiliated with the knights, merely taking advantage of the real estate. Over time, a popular trope has developed, depicted in stories and anecdotes. A scrawny but book-smart monk, a nerd, if you will, attempting to undertake the physically demanding martial training of the knights, with much humor deriving from the pairing of a burly and practical-minded knight and his new stick-limbed squire.

The reverse scenario is also common, a knight skilled in the ways of a soldier but rather book-dumb, attempting the intellectual life of a research monk, with the comedy deriving from his ignorance causing trouble for the other monks.