AN Lyn: An unusual medium amplitude δ Sct star

Simultaneous uvbyβ photometric observations of the medium amplitude δ Sct star AN Lyn have been collected and new times of light maxima have been obtained. The Fourier transform and classical O-C methods are used to analyse the pulsation of this star. The light curves are peculiar in the sense that the descending branches are steeper than the ascending ones. Amplitude variations are shown to be present from season to season. The analysis of the phase shifts between observed light and colour variations suggests that this star is a radial pulsator. In addition, intrinsic b-y, m1 and c1 values are also derived and the physical parameters are determined indicating that this variable is a nearly cold and evolved δ Sct star showing solar metal abundances and pulsating in the second overtone.