align and stack

Forums Spectroscopy Introduction to spectroscopy align and stack

Robin Leadbeater

Hi David

There’s no substitute for good seeing to get decent resolution with the Star Analyser  but with bright targets you can try using short exposures and  select, align (on the zero order or sometimes better on a prominent line if the stacking program will lock onto it) and stack as the planetary imagers do. This helps with dynamic range when using video type cameras as well as generally improving sharpness of the spectrum but the problem is that that the variations are wavelength dependent. (hence the twinking colours seen with bright stars in bad seeing) so the spectrum can still end up blurred.