Never tried this before but I had a couple of brief exposures totalling 80s [50s+30s] on M1 but taken 22 days apart and combining them would boost the data !
The Lodestar had remained attached and unmoved on the scope [except for tweaking focus] for over 8 weeks and the merge of the two images below proved perfect - even for the central pulsar inset lower left. The horizontal lines top and bottom show the respective overlap to the two shots but obviously no rotation of the two fields.
I built my DIY obsy two decades ago to combat severe light pollution and protect the permanently aligned scope. Being instantly ready-to-go is a huge bonus
Edited by nytecam, 17 February 2017 - 04:19 PM.