The spikes on the brighter stars were induced by running two strings across the front of the telescope. Normally SCT telescopes like the EdgeHD 11 used for this photo do not cause diffraction spikes. The stars from an SCT are ideally perfectly round with no spikes at all.

But sometimes diffraction spikes can give a bit of sparkle to an image. For some people anyway. And for clusters, spikes can sometimes highlight the brighter stars. So to see how it would look, I ran a couple of strings across the front of the telescope.

This recreated the effect of the secondary mirror vanes that are usually found on Newtonians and RC styles of open front telescopes. Hubble for example, is an RC design and it induces spikes in the brighter stars. So, not saying it's a good thing. Scientifically, it probably isn't. But some might like it so it was worth a try.