Pulsation and rotation in NGC 6811

The results reveal that all the targets are variable: two red giant stars with solar-like oscillations, 21 main-sequence pulsators (16 {delta} Scuti and five {gamma} Doradus stars), and 13 rotating variables. Three new {gamma} Doradus ({gamma} Dor) variables (one is a hot {gamma} Dor star) are detected in this work together with five new rotating variables.

An in-depth frequency analysis of the {delta} Scuti ({delta} Sct) and {gamma} Dor stars in the sample shows that the frequency spectra are very rich, in particular for the {delta} Sct-type variables. They present very dense frequency distributions and wide diversity in frequency patterns, even for stars being members of the cluster and with very similar location in the Hertzsprung-Russell (H-R) diagram. Rotational modulation is found for a high percentage of these main-sequence pulsating stars, which is an indication of stellar activity being common on the surfaces of these hot stars.