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Published online by Cambridge University Press: 24 July 2012
We present the internal proper motion of 6.7-GHz methanol masers in S269, an Ultra Compact HII region. The maser distribution in S269 consists of several maser groups, and the spatial structure of the main groups A and B are consistent with the past VLBI image. The remarkable result of comparing the two VLBI maps is that 6.7-GHz methanol maser distribution and velocity range within each group have been kept for eight years. Angular separation between the two groups A and B increases by 3.6 mas, which corresponds to a velocity of 11.5 km s−1.