The properties of low frequency magnetic fluctuations generated by cometary ion pickup are examined by means of one-dimensional hybrid simulations, in which newborn ions are created at a constant rate. The helicity and direction of propagation of magnetic fluctuations are investigated for various cometary ion injection angles, &agr;, relative to the solar wind magnetic field. The parameter &eegr; represents the relative contribution of wave energy density propagating in the direction away from the comet, parallel to the beam. For small (quasi-parallel) injection angles, &agr;~0¿ and &eegr; is of order unity, while for larger (quasi-perpendicular) angles, &agr;~90¿ and &eegr; is about 0.5. At intermediate angles, &agr;~60¿, &eegr; can vary between 0 and 1, depending on the wave number. The wave properties are consistent with the instabilities (right-hand cyclotron resonant modes at small &agr;, left-hand Alfven/ion cyclotron modes at large a) expected from linear theory. Consequences of these results for particle acceleration are also discussed. ¿1991 American Geophysical Union