Let AB be the major axis of the orbit, B the pericentre, F the focus or centre of motion, P the position of the body.
Barentszoon published a marine atlas of the Mediterranean, the major axis of which he reduced to 42 degrees.
The angle cp is termed the eccentric angle, and is geometrically represented as the angle between the axis of x (the major axis of the ellipse) and the radius of a point on the auxiliary circle which has the same abscissa as the point on the ellipse.
Of practical importance are the following constructions: - (I) Given the axes; (2) given the major axis and the foci; (3) given the focus, eccentricity and directrix; (4) to construct an ellipse (approximately) by means of circular arcs.
The major axis of any such aberrational ellipse is always parallel to AC, i.e.
Let JO intersect the major axis in 0 1.