The feet of orthogonal Buekenhout–Metz unitals

Abstract

In this article we look at the geometric structure of the feet of an orthogonal Buekenhout–Metz unital 𝓤 in PG(2, q 2). We show that the feet of each point form a set of type (0, 1, 2, 4). Further, we discuss the structure of any 4-secants, and determine exactly when the feet form an arc.