Discrete survey of 5-cm OH emission from planetary and proto-planetary nebulae

We have undertaken a comprehensive search for the first excited state of OH emission (J=5/2, ²Π_3/2) in Planetary and Proto- Planetary Nebulae. With the Effelsberg telescope, we confirm the detection of Vy 2-2 and we present one new detection in the pPN K3−35. This detection has been confirmed by subsequent observations made at 6035 MHz with the MERLIN interferometer. This is the first detection of 6 GHz OH maser emission from a post-AGB star.