The Maser Monitoring Organisation is a collection of researchers exploring the use of time-variable maser emission in the investigation of astrophysical phenomena. The forward directed aspects of research primarily involve using maser emission as a tool to investigate star formation. Simultaneously, these activities have deepened knowledge of maser emission itself in addition to uncovering previously unknown maser transitions. Thus a feedback loop is created where both the knowledge of astrophysical phenomena and the utilised tools of investigation themselves are iteratively sharpened. The project goals are open-ended and constantly evolving, however, the reliance on radio observatory maser monitoring campaigns persists as the fundamental enabler of research activities within the group.

Recently, remarkable progress has been made in understanding the formation of high mass stars. Observations provided direct evidence that massive young stellar objects (MYSOs), analogously to low-mass ones, form via disk-mediated accretion accompanied by episodic accretion bursts, possibly caused by disk fragmentation. In the case of MYSOs, the mechanism theoretically provides a means to overcome radiation pressure, but in practice it is poorly studied - only three accretion bursts in MYSOs have been caught in action to date. A significant contribution to the development of the theory has been made with the study of masers, which have proven to be a powerful tool for locating “bursting” MYSOs. This overview focuses on the exceptional role that masers play in the search and study of accretion bursts in massive protostars.

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 the identification of its 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.

Within the ‘earliest phases of star formation’ (EPoS) Herschel project, we observed the NH3 inversion lines of 6 very young high-mass star-forming regions at high spatial resolution (3-5″) with the JVLA. While the Herschel data provide details about the dust continuum, the ammonia data reveal the kinematics and temperatures. Here we present the exciting star-forming clump ISOSS23053 that shows multiple velocity components. We observe a prominent velocity step within the clump, which could be a sign of colliding or converging flows that triggers star formation. Furthermore, we used the JVLA in the C-array configuration to study this source in more detail and we present the first results from the new data. They support the idea of converging flows, as we observe two components in the NH3(1,1) and (2,2) line, whereas the higher excited NH3(3,3) line shows one component that links the two lower excited lines.