We imaged the excited OH maser line at 6.035 GHz associated with the 6.7 GHz methanol masers in a selected sample of high-mass young stellar objects using the European VLBI Network. The excited OH emission was found in a survey of methanol maser sources carried out since 2018 with the Torun 32-m telescope. The overlap of radial velocities of spectral features of methanol and excited OH suggested that both lines arose in the same volume of gas, therefore, we verified this hypothesis with the interferometric data. Here, we present the first images at the milliarcsecond scale of both maser transitions and identify the Zeeman pairs at the ex-OH line estimating the strength of the magnetic field in G43.149+00.013 (W49N).

In the course of following up compact methanol masers at 6.7 GHz which were found in the Torun blind survey (Szymczak et al. 2002), we discovered a ring structure in the source G23.657−00.127. This source provides interesting insights into whether methanol masers arise in rotating disks around massive stars, in their outflows, or behind shocks. By monitoring the 12.2 GHz masers, which fortunately follow the same structure, we hope to resolve the kinematics of the ring. Moreover, the symmetry of the source points to the existence of a central source. Early results on the nature of this source indicate the existence of a hyper–compact H II region.