Can the Navigator see the the Astronomicon before entering the Warp? or does he have to be inside to see?

and how often are tithes collected? yearly? bi yearly? every 5 years?

Can the Navigator see the the Astronomicon before entering the Warp? or does he have to be inside to see?

If I understand correctly the rules from Rogue Trader (corebook, p.183-184) Navigator locate the Astronomicon after vessel translates into the warp. But this applies to jump calculation, I don't see any reason why he can 't "see" the Astronomicon from real space.

and how often are tithes collected? yearly? bi yearly? every 5 years?

I think it depends on the planet. Agri world pays each growing season , while the other worlds - depending on the material.