Refined physical properties and g′, r′, i′, z′, J, H, K transmission spectrum of WASP-23b from the groundN. Nikolov, G. Chen, J. J. Fortney, L. Mancini, J. Southworth, R. van Boekel and Th. HenningA&A, 553 (2013) A26DOI: https://doi.org/10.1051/0004-6361/201321084