Abstract:
Eight new class II methanol masers selected from the 6.7 GHz Methanol Multibeam
survey catalogues I and II were monitored at 6.7 GHz with the 26m Hartebeesthoek Radio
Astronomy Observatory (HartRAO) radio telescope for three years and seven months, from
February 2011 to September 2014. The sources were also observed at 12.2 GHz and two were
sufficiently bright to permit monitoring. One of the eight sources, namely G358.460-0.391,
was found to show periodic variations at 6.7 GHz. The period was determined and tested for
significance using the Lomb-Scargle, epoch-folding and Jurkevich methods, and by fitting a
simple analytic function. The best estimate for the period of the 6.7 GHz class II methanol
maser line associated with G358.460-0.391 is 220.0 ± 0.2 day.
