of Cassiopeia the Queen at a distance of about 9,500 light years . I
had bright moon light and light pollution to contend with, but with
very steady seeing conditions . The mount was tracking perfectly on
this particular evening , notice the inner core detail . I used five
minute sub frames with matching dark frames combined with flat field
frames to reduce the effect of vignetting in the final image. I was
using narrow band filters , S11, HA, and O111. and used the Hubble
Palette for the colour data. The total exposure times was sixty
minutes for S11 and HA filters and fourty minutes for the O111 filter
Detail in the core
