$R$ to the $J$ bands (0.6–1.25 $\muup$m) obtained in late March and early May 2015. [Figure]{} \[fig:polarproj\] shows the polar projections of the $r^2$-scaled RDI IFS and IRDIS images with the positions of the shadow lanes in the IRDIS $J$-band polarized image obtained on 2015 May 2, i.e. about two weeks prior to these observations. Features A, B, and D [[notations from @Stolker2016]]{} are recovered in both polar-projected images, but feature C is only seen in the IFS image. Feature C was not seen in the SPHERE data obtained in late March 2015. The minima in the total intensity images are not as pronounced as in the polarized light images. This might be caused by sensitivity effects.

Photometry and morphology of the spiral arms
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We [used the RDI IFS and IRDIS images]{} (top panels of Figs. \[fig:ifsim\] and \[fig:irdisim\]) to derive the radial surface brightness profiles of the disk along its major and minor axes (Fig. \[fig:brightnessprof\]), assuming that the major axis has a position angle of 62$^{\circ}$ [@Perez2014]. For IFS, we analyzed [the $Y$, $J$, and $H$ spectral bands separately]{}. We used radial cuts through the disk of [1 pixel in width]{}. The conversion of the intensity into 