AN EXCITED-STATE OH MASER IN THE LARGE MAGELLANIC CLOUD

A maser at the 6.035-GHz transition of excited OH has been discovered in the Large Magellanic Cloud. It is the first extragalactic maser fou nd at this transition, and is at the position of a previously known 1. 665-GHz ground-state maser. It is stronger in the excited state than i n the ground state, a characteristic shared by only six of the 78 simi lar excited-state OH masers detected in our Galaxy. An accurate positi on for the maser and a high-resolution continuum map have also been ob tained. These show that the maser is 50 arcsec south-west of the peak of an H II region known optically as N160a (not towards N159 as was su ggested from the ground-state maser discovery measurements); it is at the location of a 3-mJy continuum radio source, probably a weak H II r egion.