Distribution of the 6.7 GHz CH₃OH maser cloudlets detected within ~1 arcsec of Cepheus A HW2. The main panel shows the distribution of the maser cloudlets (colored dots) superimposed on a HC₃N (27–26) v₇ = 1_e map (contours) integrated in the velocity range from − 7 to − 3 km s^-1  (from Jiménez-Serra et al. 2009). HC₃N contours start at 2σ by 2σ steps. The upper axis gives the linear scale of the map at a distance of 700 pc. Maser colors indicate the gas LSR velocity locally, according to the right-hand wedge. Maser groups are labeled according to Sugiyama et al. (2008b). The systemic velocity (V_sys) is set at − 4.5 km s^-1. The black star marks the HW2 position according to Curiel et al. (2006). Insets: blow-up of the local maser emission (beam size at a bottom corner) summed within the V_LSR range specified in each box (see Sect. 3). The gray logarithmic scale (top wedge) gives the brightness scale from 10σ up to the peak emission in Jy beam^-1; the black contours give the brightness levels from 10% of the peak emission by 10% steps. The red arrows trace the proper motion vectors of the maser cloudlets; the arrow length indicates the position reached after a time of 40 yrs at the average velocity of 1.7 km s^-1. Note that a few proper motions are associated with faint maser cloudlets that are not visible in the summed maps.