Some of the optical state parameters extracted from the data. From the top, Δx is the spectral drift relative to the first exposure, calculated using cross-correlation of the raw spectra, Δφ is the instrument rotation angle, seeing is measured as the product of full width half maximum from the Gaussian profile along the spatial axis and the pixel scale in arcsec and X is the airmass. These parameters are extracted to check for any possible correlation with the systematics in the light curve. The grey shaded region shows the duration of transit.