Possible Precession Motion in the Bipolar Proto-Planetary Nebula IRAS 17441-2411

Mid-infrared imaging of two bipolar proto-planetary nebulae, IRAS 17150-3224 and IRAS 17441-2411, was obtained with the Gemini telescope. Dust emissions are detected in both the bipolar lobes and in the equatorial region of IRAS 17441-2411. In particular, the orientation of the axis of the infrared torus is found to be offset by 23° from the bipolar axis. If the torus is responsible for or related to the collimation of the bipolar outflow, this raises the possibility that the outflow has undergone precession over the last 100 years.