[Paul Haese]

I need to outline this a little to make sense.

I currently have 60 frames at 10 minutes in Ha of Thor's helmet and at -15c. I have been using CCDstack for stacking. I need to do this in batch lots as doing 30 frames the program runs out of memory or will not allow more numbers of frames.

So stacking in batch lots of 10 and summing I cannot get rid of all the noise in the image. This is in part because I have to do data rejection on each run to eliminate the hot pixels from the data. If I just do data rejection from the first runs and then none in the later runs the noise disappears but the hot pixels are in rows. If I do data rejection on each run I get latent noise (see crop image).

What do I do to get rid of the noise and the hot pixels. I would have thought 10 hours of Ha data the noise would be none existent. What on earth am I doing wrong? Could it be because the flux level is low on a 10 minute sub and using the Ha data as my luminence is just causing the program to stretch the data and this shows the noise. Does the data need to be say 20 minutes subs?

Some thoughts and advice would provide an interesting discussion on this subject.