Pretty cool! I've always had kind of a thing for astrophotos. Gotta love the 6D for those low light shots. I've used my 6D some for night shooting.
Curious what lens you are using and your ISO setting. I've thought about getting one of those trackers, but I can just crank the ISO up to 3200 or so on the 6D and keep the exposure down to a few seconds to minimize any star trails. It also helps if you want to include any foreground subjects in the photo and keep them sharp.
After much research, I recently got a couple of the Rokinon lenses for astrophotography. They are manual focus only, but that is not a big deal for astrophotos since you generally need to focus manually anyway. They are quite sharp even wide open and don't distort the stars around the edges like a lot of lenses do.
Last month I went out and found a remote old cemetery to shoot some Milky Way photos. This was shot using the Rokinon 24mm f1.4, using f2.8 at 20 seconds and ISO 3200.