6.035GHz OH observations of two IRAS

The observations were conducted between 2008 October and 2010 January with the 305m Arecibo Telescope in Puerto Rico. We detected two flare events, one in 2009 March and one in 2009 September to November.

The OH maser flares are not simultaneous with the H_2_ CO flares, but may be correlated with CH_3_ OH flares from a component at corresponding velocities. A possible correlated variability of OH and CH_3_ OH masers in IRAS 18566+0408 is consistent with a common excitation mechanism (IR pumping) as predicted by theory.