WOW!! Yes is really awesome, I did something similar but only using 4 and 3 seconds, very far from your image, but I was using a very cheap mount and was not able to hold more than 3 or 4 seconds.... Can you tell me what gain setting did you use?
You can see my post here http://zwoug.org/viewtopic.php?f=22&t=6956.
Thanks