Advent amateur astronomer witnessed phenomenonI saw a bright white flash of light to the right of cepheus. Ignoring it thinking it was a comet from the corner of my eye I seen it flash again. It was very high up and continued at a steady velocity moving right of cepheus. It was different from an aircraft or satellite because it would only light up with white light every 20-30 seconds and while doing so it would also glow for 3 seconds allowing me to make out the shape.