Soleil = (4, 0)
B = Point(xAxis)
C = (12, 0)
c = Ellipse(Soleil, B, C)
A = Point(c)
a = Line(A, Soleil)
b = Segment(A, Soleil)
e: 100.0 / b^(2.0)
D = Point(Circle[A, e])
d = Segment(A, D)
α = Angle(Soleil, A, D)
F = Rotate(D, -(α), A)
u = Vector(A, F)