The GTC exoplanet transit spectroscopy survey - XI. Possible detection of Rayleigh scattering in the atmosphere of the Saturn-mass planet WASP-69bF. Murgas, G. Chen, L. Nortmann, E. Palle and G. NowakA&A, 641 (2020) A158DOI: https://doi.org/10.1051/0004-6361/202038161