Nice that you shared this image cause it pleasures the eyes!
You have got an awesome tracking precision to achieve 20 minute exposures with that type of mount; WOW!!
Please post the completed combinated Image also, will be a nice Pic
CGEM Mount, C11, TS UNC 10" f5, TS Carbon Triplet Apo 90/600, TSOAG 9mm
ATIK 383L+ & EFW2, Lodestar, QHY6,
Observation site 20 km SW of Luxemburg City