Discovery of the first Ap star in an eclipsing binary system

We report the discovery of a very special object, the first star of its kind. HD 99458 appeared to be a chemically peculiar star of Ap type, showing overabundances of Si, Ti and other heavy elements which are concentrated into spots. The spots produce rotational modulation of light variations. In addition, the star shows pulsations of a ? Scuti type, which has never before been reported in Ap stars. The star is in a binary system with a red-dwarf companion, which is also very rare among magnetic chemically-peculiar stars. In this paper we discuss new observations and results concerning the pulsation period and chemical peculiarity of this object.