Omri Alon,
It's the only opening I could find large enough without too many trees getting in the way so I shot with what was available.
fiveFPS,
At 14mm it's the longest I can expose without noticing star trails, well technically I could expose for 42" seconds at 14mm but I like to be a little conservative. Next week when I make it back out to the desert I'll take a shot at 60" seconds and post the results here. I also haven't stacked photos with my 6D yet so I may try that out as well. I'd like to see a comparison with the 6D between a single exposure and some stacked images.