Periodicity in Class II methanol masers in high-mass star-forming regions
Periodicity in Class II methanol masers in high-mass star-forming regions
We report the results of 10 years of monitoring of six regularly varying 6.7 GHz methanol masers using the Hartebeesthoek 26-m telescope. Observations were done at intervals of 1–2 weeks, with faster sampling during flaring episodes. Four of the sources were also monitored at 12.2 GHz and show correlated variations. …