A comprehensive study of the δ Scuti star AN Lyncis

National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China

Corresponding author: aiying@bao.ac.cn

Received: 25 September 2000
Accepted: 17 January 2002

Abstract

We present new time-series CCD photometry on the δ Scuti star AN Lyn. Analyses based on all the available data show that the amplitude of the main frequency increased from 1994 to 2000 at a rate of 0.006 mmag yr^-1. Considering all the existing amplitudes, the amplitude variations seem sinusoidal since 1980. In both periods of 1980–1983 and 1994–2001 with data available the amplitudes increased linearly with time. The amplitudes in the earlier 1980s were higher and they increased at a higher rate than those in 1994–2001. Amplitude variations of the other frequencies are also present from season to season. The light variation of AN Lyn can be explained currently by amplitude variability plus multiperiodic pulsation. However, no conclusion can be drawn regarding change of periods and new oscillation contents. The two independent frequencies  cycle d^-1 and  cycle d^-1 are confirmed and are suggested to be the solution of the light variation of AN Lyn. The mixture of radial and nonradial modes of the two frequencies most likely characterize the pulsation of the star.