[Leica] Comet pic, software to eliminate earth's rotation?

[Peter Klein]

The Seattle area finally had a clear-ish night. I went out to a bluff 
overlooking Puget Sound to attempt to see and photograph Comet 
Tsuchinshan-Atlas. The comet has faded to below naked-eye visibility, 
and required exposures of 3-8 seconds. So I ended up with the stars and 
comet head elongated into little lines.  Is there any software that will 
resolve this "motion blur?" Focus Magic can do something like this, but 
only over about 20 pixels. My "star trails" are  longer.

Sized down a bit, it looks reasonable. Five seconds at f/3.3, ISO 1600, 
Olympus EM-1 MK II and 50-200 f/2.8-3.5.  Couldn't see a thing, could 
barely detect it with binoculars. Focus by trial and error.
https://www.flickr.com/photos/24844563@N04/54087604179/in/dateposted-public/

I am now thawing out my hands...

--Peter