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The Setting: A distant planetary system consists only of two planets, Iapetus and Atlas orbiting about the star GXZ-216. At one particular night, the two planets are observed to be aligned with the star in such a way, that Atlas is causing a stellar eclipse on the surface of Iapetus.
The Data: It is estimated that the two planets are at a distance of 90 million kilometers, and observations have shown that both are at the perihelion of their orbits (i.e. their distance from the star is minimal). Atlas' distance from GXZ-216 is estimated to be 30 million kilometers. A full year of Atlas is recorded to take 200 Earthly days.
The Question: At a later time, Atlas was observed in the aphelion of its orbit, i.e. the point of maximal distance from the star. Can you calculate the location of Iapetus from GXZ-216 at that particular time?