Sequator is a free software which can track stars on multiple images, align stars and stack them.
If you don't have an equatorial mount, by stacking non-blur star images in short-time exposures, the result will be almost similar to long-exposure on an equatorial mount. However, Sequator can control the exposure properly by auto-brightness or HDR-mode output, in 16-bit TIFF for further post processing. Additionally average random noises, rather than over-exposed on a physical equatorial mount.... More Info »
Easy; user friendly
Automatic determination for best parameters
Capable under heavy light pollution
Powerful correction for wide-angle & complex distortions
Intelligent sky mask
Foreground detection & stacking
Star light enhancement function
Light pollution reduction function
Support star trails mode
Batch processing for time-lapse
Support RAW & 16-bit TIFF
Sequator will not provide too many confusing options; in contrast, strictly select the most effective features for you. Endeavor to automatically determine best parameters, save the time from boring trials. "Simple but powerful", is the core philosophy of Sequator.