A study of variability of the marginal Am star HD 176843 observed in the Kepler field

We present results of a study of variability of the marginal Am star HD 176843 observed in the Kepler field. Kepler photometry and ground–based spectroscopy are used to investigate the light variations of the star. HD 176843 is classified as a marginal Am star that shows δ Sct type pulsations. From an analysis of the Kepler time series, we find that the light curve of HD 176843 is dominated by three modes with frequencies f 1 =0.1145, f 2 =0.0162 and f 3 =0.1078 d−1. The amplitude of the radial velocity variations of about 10 km/s is much more than the radial velocity errors and allows us to conclude clear radial velocity variations. Using the radial velocity data and the adopted spectra, the orbital solution of HD 176843 is also obtained with an orbital period of 34.14 days. However, the available photometric data show no significant evidence for any possible motion in the binary system.