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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def observe(self, body):
 """Compute the `Astrometric` position of a body from this location. To compute the body's astrometric position, it is first asked for its position at the time `t` of this position itself. The distance to the body is then divided by the speed of light to find how long it takes its light to arrive. Finally, the light travel time is subtracted from `t` and the body is asked for a series of increasingly exact positions to learn where it was when it emitted the light that is now reaching this position. <Astrometric position and velocity at date t> """

        p, v, t, light_time = body._observe_from_bcrs(self)
        astrometric = Astrometric(p, v, t, observer_data=self.observer_data)
        astrometric.light_time = light_time
        return astrometric