The Jerabek center X_125 (center of the Jerabek hyperbola) lies on the nine-point circle. The Jerabek antipode is the antipode of this point on nine-point circle. It has triangle center function α_113 = sin B sin C((sin B)/(cos B - 2cos A cos C) + (sin C)/(cos C - 2cos A cos B)) and is Kimberling center X_113.

Feuerbach antipode | Jerabek hyperbola | Kiepert antipode