|In the arclength plot, 'arclength' is our way of parametrizing
the position of the star on the detector in one dimension.
The arclength plot essentially shows the dependence of flux on position
and how successful our technique is at removing it.
If the black points form a tight relation and the orange dots fit through it well,
then the correction is likely of high quality.
In the image plot, the region outlined in red is the photometric aperture,
and the green dots are the image centroid positions.
The image itself is the coadded image from all
K2 observations after the spacecraft attained fine guiding control.