Thanks for all your kind comments folks! I had expert with the polar alignment
not sure I'm ever going to be able to replicate it
I've been tinkering a bit with the stacking and if I'm brave enough might post an "update" later. I took more frames than this (about another 15 minutes) but they were below the cutoff I used in DSS. Is there a way to use the colour information from these without bloating the stars?