Infrared variability, maser activity, and accretion of massive young
  stellar objects
  Methanol and water masers indicate young stellar objects. They often exhibit
flares, and a fraction shows periodic activity. Several mechanisms might
explain this behavior but the lack of concurrent infrared (IR) data complicates
to identify the cause. Recently, 6.7 GHz methanol maser flares were observed,
triggered by accretion bursts of high-mass YSOs which confirmed the IR-pumping
of these masers. This suggests that regular IR changes might lead to maser
periodicity. Hence, we scrutinized space-based IR imaging of YSOs associated
with periodic methanol masers. We succeeded to extract the IR light curve from
NEOWISE data for the intermediate mass YSO G107.298+5.639. Thus, for the first
time a relationship between the maser and IR variability could be established.
While the IR light curve shows the same period of ~34.6 days as the masers, its
shape is distinct from that of the maser flares. Possible reasons for the IR
periodicity are discussed.
