Proceedings of the second helas international conference: helioseismology, asteroseismology and mhd connections vol:118 pages:12077-12077
Journal of Physics Conference Series
International Conference on Helioseismology, Asteroseismology and MHD Connections (HELAS II) Gottingen, GERMANY, AUG 20, 2007-AUG 24, 2008
To optimise the science results of the asteroseismic part of the CoRoT satellite mission a complementary simultaneous ground-based observational campaign is organised for selected CoRoT targets. The observations include both high-resolution spectroscopic and multi-colour photometric data. We present the preliminary results of the analysis of the ground-based observations of three targets. A line-profile analysis of 216 high-resolution FEROS spectra of the delta Sct star HD 50844 reveals more than ten pulsation frequencies in the frequency range 5-18 d(-1), including possibly one radial fundamental mode (6.92 d(-1)). Based on more than 600 multi-colour photometric datapoints of the beta Cep star HD 180642, spanning about three years and obtained with different telescopes and different instruments, we confirm the presence of a dominant radial mode nu(1) = 5.48695 d(-1), and detect also its first two harmonics. We find evidence for a second mode nu(2) = 0.3017 d(-1), possibly a g-mode, and indications for two more frequencies in the 7-8 d(-1) domain. From Stromgren photometry we find evidence for the hybrid delta Sct/gamma Dor character of the F0 star HD 44195, as frequencies near 3 d(-1) and 21 d(-1) are detected simultaneously in the different filters.