2019 February 19
In recent years a small group of methanol maser sources showing periodic variability have been identified. There is ongoing discussion on causes of this type of behavior, but none of the explanations are satisfactory. Discovery of source G107.298+5.639 showing alternating and periodic flares of 6.7GHz methanol and 22GHz water vapor masers can give us a clue to processes leading to observed periodicity. Recently we confirmed OH maser periodicity in this object. Result of multiepoch EVN observations of methanol emission in G107.298 will be presented.