The precession of the HH 111 flow in the infrared
  We present Spitzer IRAC images of the HH 111 outflow, that show a wealth of condensations/knots in both jet and counterjet. Studying the positional distribution of these knots, we find very suggestive evidence of a mirror symmetric pattern in the jet/counterjet flow. We model this pattern as the result of an orbital motion of the jet source around a binary companion. From a fit of an analytic, ballistic model to the observed path of the HH 111 system, we find that the motion in a binary with two approx. 1 Msolar stars (one of them being the HH 111 source), in a circular orbit with a separation of approx. 186 AU would produce the mirror symmetric pattern seen in the outflow. 
A. Noriega-Crespo (1), A. C. Raga (2), V. Lora (3), K. R. Stapelfeldt   (4) and S. J. Carey (1) ((1) SSC, Caltech, (2) ICN U...
astro-ph.SR