Surface brightness profiles of 67P for March 23 and April 14. The brightness corresponds to the measured brightness, no correction for heliocentric and Rosetta-comet distance is applied. The open circles are the comet profile and the solid line is the star profile. The increase of brightness at ρ > 40′′ in the March 23 profile and at ρ > 50′′ in the April 14 profile is caused by background stars. The error bars associated to each datapoint are smaller than the symbol used, thus they are not visible in the plot.