Who is Arch-astronomer of Krull from The Colour of Magic and what is their importance?

Krull's Arch-astronomer is responsible for overseeing the construction of the Potent Voyager. He commissions Goldeneyes to make the vessel, and quickly disposes of the man once the ship is built. The Arch-astronomer isn't going to take any chances that a similar ship might be constructed. Unfortunately, AA busily makes deals with everyone he meets along the way and gets himself into trouble. In the end, he is eaten by the Luggage.