Reply To: To stack or not to stack, which is best?

Hi John,
If you are combining errors/uncertainties from individual images then you also need to divide by the square root of the number of images.
A useful check is to calculate the standard deviation on the magnitudes derived from the individual images. This won’t be identical but should not be vastly different. The standard deviation with give you a direct estimate of the random error, and large differences could indicate systematics that are over or under estimated in the formula used to calculate the individual magnitude uncertainties.
Best wishes,
Andy

• This reply was modified 1 month, 1 week ago by Andy Wilson.