Non-radial pulsation of the δ Scuti star UV Trianguli

We present the results of a three-year photometric study of the δ Scuti star UV Trianguli. Our data sets consist of 9378 differential measurements in Johnson V together with a few data collected into the Strömgren uvbyβ system. UV Tri is at least a biperiodic variable. The two best-fitting frequencies, f1= 9.3298 d−1 and f2= 10.8513 d−1, are still not the complete set of pulsation frequencies representing the light variations of the star. A suspected third frequency might present in the star. Several ‘anomalous cycles’ are observed in the light curves. They seem real, but are aperiodic. We derive the colour indices and physical parameters for the variable and conclude that it is a Population I δ Sct star with normal metal abundance ([Me/H]= 0.0 ± 0.1 dex) evolving on its main-sequence stage at an early evolutionary phase before the turn-off point. Finally, we compare the observed oscillation frequencies with theoretical models. The two pulsation modes of UV Tri are likely to be non-radial gravity modes.