2324 20160701171703.0 ASTROimport-481 Briquet, M. 2009 Ground-based observations of the beta Cephei CoRoT main target HD 180642 We present the preliminary results of a detailed study of ground-based photometric and spectroscopic observations dedicated to the ß Cephei CoRoT main target HD~180642. Besides the non-linear dominant radial mode several low-amplitude modes are detected in both kinds of datasets. Our aim is to derive the wavenumbers (l,m) of these modes, as additional constraints to the CoRoT pulsation frequencies, for forthcoming asteroseismic modelling of the star. Uytterhoeven, K. Aerts, C. Morel, T. De Cat, P. Miglio, A. Mathias, P. Lefever, K. Poretti, E. Martín-Ruiz, S. Paparó, M. Rainer, M. Carrier, F. Gutiérrez-Soto, J. Valtier, J. C. Benko, J. M. Bognár, Z. Amado, P. J. Suarez, J. C. Rodriguez-Lopez, C. Garrido, R. Communications in Asteroseismology 158 2009 292 http://esoads.eso.org/abs/2009CoAst.158..292B published in REFERD