A Pulsational Time-evolution Study for the δ Scuti Star AN Lyncis

This paper presents a large amount of observations for the δ Scuti star AN Lyncis carried out in 2001–2012. The extensive observations include two tri-continent campaigns coordinated in 2002 and 2011, respectively, and several single-site contributions throughout the period. The data in total have more than 104100 raw CCD frames and photoelectric records, which consist of 165 nights (about 816 hours) spanning over 3778 days. The final reduced light curves have more than 26500 data points (including those 3462 unpublished BYU data), from which we determined 306 new timings of maximum light. A time-dependent behaviour study based on all available data indicates cyclic amplitude variability as well as period change [for the main periodicity]. Orbital sinusoid fittings to (O-C) residuals and pulsation amplitudes may account for their variations being caused by the light-time effect of AN Lyn in a binary system. The orbital period is about 26–30 years. Current results support the binarity of AN Lyn, first suspected by Zhou (2002). We further show the detailed time evolution structure of the pulsation of AN Lyn as function of both time and period through wavelet analyses.