Modeled planet, star, and total intensities, photocenter and FWHM spectra (from top to bottom) when the slit is oriented towards the planet’s position and perpendicular to it (left and right panels). The black line refers to the fiducial values for LkCa 15 of the contrast in the continuum and in Hα(5.2 and 8 magnitudes), the star–planet separation (93 mas), and the seeing (1.2″). The colored lines refer to variations in c_line (red), c_cont (blue), s (green), and seeing (violet) within error bars (dotted and dashed lines for the corresponding upper and lower limits; see text). The horizontal dashed lines in the photocenter panels represent our detection limits. The FWHM spectra plotted are ~1 order of magnitude below detection limits.