( catalog K~3-35 ) is a planetary nebula ( PN ) where H _ { 2 } O maser emission has been detected , suggesting that it departed from the proto-PNe phase only some decades ago .
Interferometric VLA observations of the OH 18 cm transitions in ( catalog K~3-35 ) are presented .
OH maser emission is detected in all four ground state lines ( 1612 , 1665 , 1667 , and 1720 MHz ) .
All the masers appear blueshifted with respect to the systemic velocity of the nebula and they have different spatial and kinematic distributions .
The OH 1665 and 1720 MHz masers appear spatially coincident with the core of the nebula , while the OH 1612 and 1667 MHz ones exhibit a more extended distribution .
We suggest that the 1665 and 1720 masers arise from a region close to the central star , possibly in a torus , while the 1612 and 1667 lines originate mainly from the extended northern lobe of the outflow .
It is worth noting that the location and velocity of the OH 1720 MHz maser emission are very similar to those of the H _ { 2 } O masers ( coinciding within 0 { \hbox to 0.0 pt { . } } ^ { \prime \prime } 1 and \sim 2 km s ^ { -1 } , respectively ) .
We suggest that the pumping mechanism in the H _ { 2 } O masers could be produced by the same shock that is exciting the OH 1720 MHz transition .
A high degree of circular polarization ( > 50 % ) was found to be present in some features of the 1612 , 1665 , and 1720 MHz emission .
For the 1665 MHz transition at \sim +18 km s ^ { -1 } the emission with left and right circular polarizations ( LCP and RCP ) coincide spatially within a region of \sim 0 { \hbox to 0.0 pt { . } } ^ { \prime \prime } 03 in diameter .
Assuming that these RCP and LCP 1665 features come from a Zeeman pair , we estimate a magnetic field of \sim 0.9 mG within 150 AU from the 1.3 cm continuum peak .
This value is in agreement with a solar-type magnetic field associated with evolved stars .