X(2), X(67), X(141), X(524), X(9076), X(10415)
X(9076) on the circumcircle
K103 is the only pivotal circular cubic locus of M such that the trilinear polars of M and its isoconjugate M* are parallel. See Special Isocubics §4.3.5.
The pole and the pivot are both X(67) hence the isopivot is G and the tangents at A, B, C are the medians of ABC.
K103 is the only circular pK with coincident pole and pivot. Its singular focus is X(14654).
K103 is a member of the class CL007 of cubics.