Star-like point of light, flashing periodically, erupts into bright sparkle after 30 minutes.After a hard day, I thought it might be nice to sit and enjoy a small pot of tea in my back yard, which faces north. I first went out at twilight, around 9:30. I have a good view of the eastern and northern sky. Portions of the western sky are blocked by trees. My house blocks the southern sky. Directly overhead was one of the bright stars of the constellation Draco, the first star in my field of view bright enough to be visible. It was still too bright out for other stars to be visible. As I unwound and watched the sky, I thought I saw a flash or twinkle in the northern sky, almost due north, about 35 - 40 degrees up. Perhaps the sun glinting off a satellite, I thought, or maybe the navigation lights of a high-altitude jet aircraft crossing the country. Intrigued, I scanned for signs of an aircraft. About half a minute later, I saw it again, in exactly the same place. That ruled out a plane a satellite or, at least, the same plane or satellite, but what are the chances of two of either reaching that same spot within half a minute? Could be my eyes playing a trick on me, can't rule that out. Half a minute or so later, another flash or twinkle. A few minutes later, same thing. Always in exactly the same spot, near as I could tell.I got distracted for awhile by some things in the yard and inside the house, but was back watching the sky a little before 10:00. By that time, it was dark enough that I could make out more stars. There was no star visible where I saw the twinkle. There would be a couple of stars in the constellation Camelopardalis that would be visible in that area most nights, but it's still too light out to see any stars around there at 10:00 at this time of year. Toward the northeast, one of the brighter stars of Cassiopeia was now visible. Further east, I saw a light aircraft with flashing navigation lights flying level, headed due west. I watched the small plane cruise through the sky, noticing that there was another small plane flying a parallel path to the south. I figured one of them, probably the slower and more southerly one, was Saskatoon's police patrol plane, which is out most nights. It looked like the more northerly plane could have been preparing for an approach to the airport. After a few moments it reached the part of the sky where I saw the strange twinkling earlier, so my eyes were now drawn back to that area. Suddenly there was another flash of light from the same spot as before, but this time it was much brighter. The shape was not like a twinkling star, but more like a line or thin cylinder or dumbbell kind of shape, consisting of two very bright twinkly points, shining momentarily like sparklers on a birthday cake, with a straight, thin bright or shiny line joining them. The two bright points were maybe two degrees apart, about the width of my little finger at arm's length. The phenomenon lasted only a fraction of a second, maybe an eighth to a quarter of a second at most, but long enough that it was unmistakable. It made me jump. I watched the sky for several minutes, but did not see any other twinkles or flashes. Frankly, I began feeling a little uneasy once the bright flash occurred, and I packed up my tea and lawn chair and came into the house by about 10:15.I suspect that whatever it was, was very high in the sky. I would be curious to know if anyone in a more northerly community had seen this, and how it would have looked from their vantage point.