High-precision photometry by telescope defocussing - II. The transiting planetary system WASP-4

John Southworth, T. C. Hinse, M. J. Burgdorf, Martin Dominik, A. Hornstrup, U. G. Jorgensen, C. Liebig, D. Ricci, C. C. Thone, T. Anguita, V. Bozza, S. Calchi Novati, K. Harpsoe, L. Mancini, G. Masi, M. Mathiasen, S. Rahvar, G. Scarpetta, C. Snodgrass, J. SurdejM. Zub