I have a set of images from two different filters which belong to the STIS camera.
I can align these images when I intend to align them for each individual filter. However, by the time I align the images from both filters, I face a terrible problem.
It is vivid even to a naked eye there is some sort of a misalignment. As you can see in the master image (here https://drive.google.com/file/d/0BwkVJ8tgy-7bTUpHM1lYcjZONUE/view?usp=sharing
) ,it is like each star has repeated itself three to four times.
FYI: I use tweakreg to align my set of images and astrodrizzle to stack them.
Could anyone help me to address this problem?