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Old 10-08-2019, 08:48 AM
Frankenstein Monster is offline
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Join Date: Apr 2004
Location: Europe
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Quote:
Originally Posted by DPRK View Post
...you can see for instance how he rules out a parabolic orbit for Uranus, demonstrating it must be a genuine planet.
Again from a poor understanding of French, I think it goes like this:

He takes two observations of Uranus with the largest separations in time.

He fits them to a parabolic orbit (I think also in the plane of the ecliptic) with a perihelion distance of 10 times that of earth orbit.

He shows that the observations inbetween do not match what they would have been with such an orbit (differences of as much as 20 to 25 minutes of arc).

He also tries a perihelion with 8 times that of earth orbit and shows that it's not much better.

He doesn't spell out his formulas or calculations. I suppose the formulas are just plain obvious to astronomers of that era. I imagine it's really just high school trigonometry.