Freelancer Timeline

[Igiss]

We know in which direction Earth is from Sirius, following the track of Hispania sleeper ship. Obviously, Earth should be in the direction of Crete.

One of the Kusari rumors say that people come to Kusari to see Sirius. While there's no such star in the actual game, it can be presumed that Sirius is somewhere in Kusari, perhaps in a system not present in-game ("empty" system).

However, Kusari is quite a long route from Crete. And Sirius is one of the closest stars from Earth. Since it's apparent that "Sirius sector" is much more than stars marked on the map (multiple stars without planets, unexplored, containing no jump holes etc), I'd rather say that Sirius is not present in the area of Freelancer map at all. It may indicate a direction where sleeper ships were going, but not much more.