si = a,-a,…; a = -0.1453i
Center: -0.6335+0.3092i; Zoom = 0.4
I did a manual search, (meaning I created a lot of low resolution images) to find the point where the two shapes collide. It happens at some point between here and when a = -0.1450i. The interesting space between the two shapes is very narrow. I set the aspect ratio to 2 to stretch the image horizontally.