2001ApJ...557L.109G

We present Very Large Array observations of H₂O and OH (1612 MHz) maser emission made toward the proto-planetary nebula OH 231.8+4.2. The H₂O observations show two features at v_LSR of 23.1 and 44.5 km.s^–1, located at α(1950)=07:39:58.98±0.01s, δ(1950)=-14°35'42".0±0".1, coinciding in position within error with the SiO (v=1; J=2-1) maser position recently given by Sánchez Contreras et al. The H₂O and SiO masers are most likely tracing the position of QX Pup, the Mira variable near the center of OH 231.8+4.2. This position is, however, clearly offset by ∼1" from the axis of the bipolar outflow traced by the OH maser emission. The OH (1612 MHz) maser emission spectrum shows three main components at v_LSR of 5.8, 20.0, and 27.4 km.s^–1, distributed over a region of 2" whose position and kinematics appear to trace the bipolar outflow of this source. These results suggest the presence of a binary system: one invisible star powering the bipolar outflow and the other, the Mira star QX Pup, associated with the H₂O and SiO masers. However, this scenario requires that the two stars have evolved at very similar rates (implying very similar masses).