I was in my back-yard waiting for my dogs to do their business. I noticed above me in the sky were 2 single engine airplanes. I started to watch them because they were flying pretty close to each other. AS they started to pass out of view, I noticed an object thousands of feet higher than the airplanes. It was completely motionless. I watched the object for 4-5 minutes. I have never seen a star during the day but I hear its possible sometimes. So I thought if it were a star then it would still be there if I looked away. I looked away for a second and then back again. The object was gone. I scanned the rest of the sky over and over, and couldnt see the object anywhere. It appeared to be just a circular white object. I couldnt see much more than that. It also appeared to by much higher than any airplane I've seen fly.