K-band magnitude difference between the first and second observation (or second and third in the case of CenA-dE1), against the combined dereddened K magnitude. The target galaxies are ordered by increasing luminosity. We display the magnitude difference for candidate AGB stars, plus for those stars that lie at the edges of the selection boxes but show variability (green dots). For CenA-dE1, the latter turn out to be probable background galaxies after visual inspection and have a black cross on top of the circle (see text for details). Blue objects are AGB candidates for which the magnitude varies by more than three times the combined photometric errors of the individual measurements in the two observations (or in any combination of observations for CenA-dE1). Finally, for both CenA-dE1 and SGC1319.1-4216 one AGB candidate is not shown since it has a poor quality measurement in one of the two plotted K-bands.