Sagittarius ends autumn, mutable and fire — the last stretch of shortening days before the solstice reverses them.
Jupiter rules it, as it rules Pisces: expansion in its outward register here, and its dissolving one there.
The Sun crosses the galactic centre while in Sagittarius, at roughly 27° of the sign. That is a real alignment and a coincidence of perspective — nothing about it changes the ephemeris.
Traditionally attributed
Expansion, conviction, restlessness, and a talent for overshooting.
Listed because it is what the tradition says, not because this site can check it. Everything above this line is geometry; everything in it is convention.