Overlays of the velocity field images of the λ3 mm ²⁸SiO v = 1, J = 2−1 emission of January 24, 2011 and both the λ7 mm ²⁸SiO v = 1, J = 1−0 and v = 2, J = 1−0 maser emission of October 7, 2002. The same color scale is used for both wavelengths, and the velocity fields seem continuous and consistent with each other. The cross indicates the estimated position for Source I. The white boxes delimit the extent of the λ3 mm emission.