Not a bad start but I think you need more shots!
But longer exposures as well! I assume you're stacking so many short exposure frames because you don't have a tracking mount...?
Unfortunately digital cameras have what is called the "noise floor" which sets a lower limit on exposure time for single frames for a given scene. If you go below that limit, you get virtually all noise and no signal, and stacking won't help, because you'll be stacking mostly just noise on noise, and just getting more noise in the end result. What this means is that you cannot substitute one long exposure with multiple shorter ones unless the short ones go well above the noise floor.
Bert is our resident SMC master! He can tell you how it's done!
