Constellation:

Scorpius

Character:

A mysterious woman, called Trista in the English anime. She appears first as Sailor Pluto, the Guardian of Time, who has the task of protecting the Space-Time Door from unauthorized travelers. It is only later that she appears on Earth, living as a college student. She has a distant personality and can be very stern, but can also be quite friendly and helps the younger Sailor Senshi when she can. After so long at the gate of time she carries a deep sense of loneliness, although she is close friends with Chibiusa.

Source from Wikipeida