Talk abstract details

The CoRoT mission is giving a strong acceleration in the number of the frequencies detected in the light curves of Delta Sct stars. For instance, the analysis of the data obtained on HD 50844 (V=9.1, observed during 58 d) shows us that we need several hundreds of excited modes to explain the very dense power spectrum. This result has been followed by others on Delta Sct stars observed continuously for 150 d. We will emphasize the cases of very fast rotators ($v \sin i > $150 km~s$^{-1}$) and of Delta Sct stars in binary systems. For the bright targets ($V<$9) of the CoRoT asteroseismic programme we will also compare the photometric results with the spectroscopic ones (observations performed with FEROS and HARPS instrumets). This comparison greatly helps in the mode identification and in the verification of the effectiveness of the cancellation effects in the high $\ell$-degree modes. On the basis of the spectroscopic observations we obtained the atmospheric parameters, chemical abundances of elements, and rotation velocities of about 20 Delta Scuti stars. The atmospheric parameters (effective temperature, surface gravity, microturbulence velocity) were determined by using both spectroscopic methods (including metal lines and Balmer profiles) and Stromgren photometric indices.