Distribution of VVV-PSF sources in the vs. plane. The Miras identified by Matsunaga et al. (2009, labeled MiraMat in the plot) are shown as blue circles. The region marked by dashed lines corresponds to the one from which we extracted our initial Mira candidates. The latter, upon further analysis and inspection, eventually led to our final selection of Miras, shown in this plot as orange squares. The maximum number of targets per pixel is 61 697 in this plot, corresponding to the dark orange-red region in the main panel.