Results from the most extensive study of the time-evolving dust structure around the prototype “ Pinwheel ” nebula WR 104 are presented .
Encompassing 11 epochs in three near-infrared filter bandpasses , a homogeneous imaging data set spanning more than 6 years ( or 10 orbits ) is presented .
Data were obtained from the highly successful Keck Aperture Masking Experiment , which can recover high fidelity images at extremely high angular resolutions , revealing the geometry of the plume with unprecedented precision .
Inferred properties for the ( unresolved ) underlying binary and wind system are orbital period 241.5 \pm 0.5 days and angular outflow velocity of 0.28 \pm 0.02 mas/day .
An optically thin cavity of angular size 13.3 \pm 1.4 mas was found to lie between the central binary and the onset of the spiral dust plume .
Rotational motion of the wind system induced by the binary orbit is found to have important ramifications : entanglement of the winds results in strong shock activity far downstream from the nose of the bowshock .
The far greater fraction of the winds participating in the collision may play a key role in gas compression and the nucleation of dust at large radii from the central binary and shock stagnation point .
Investigation of the effects of radiative braking pointed towards significant modifications of the simple hydrostatic colliding wind geometry , extending the relevance of this phenomena to wider binary systems than previously considered .
Limits placed on the maximum allowed orbital eccentricity of e \stackrel { < } { { } _ { \sim } } 0.06 argue strongly for a prehistory of tidal circularization in this system .
Finally we discuss the implications of Earth ’ s polar ( i \stackrel { < } { { } _ { \sim } } 16 ^ { \circ } ) vantage point onto a system likely to host supernova explosions at future epochs .