Even astral configurations
Summary: A configuration \((p_q,n_k)\) is a collection of \(p\) points and \(n\) straight lines in the Euclidean plane so that every point has \(q\) straight lines passing through it and every line has \(k\) points lying on it. A configuration is astral if it has precisely \(\lfloor\frac {q+1} {2}\rfloor\) symmetry classes (transitivity classes) of lines and \(\lfloor\frac {k+1}{2} \rfloor\) symmetry classes of points. An even astral configuration is an astral configuration where \(q\) and \(k\) are both even. This paper completes the classification of all even astral configurations.
scientific article; zbMATH DE number 2107479