Flashing light, varying intensity, moving east from costallation CassiopeiaTook the dog out about 8:00 PM and was looking at the Milky Way when I noticed a bright flash of light lasting 1-2 seconds a few degrees due east of the constellation Cassiopeia. Thought it might have been an Iridium Flare. I would estimate the magnitude about -4 or -5 with a bluish color. About 30 seconds later it flashed again, not as bright and slightly more east of first sighting. This "flashing" continued for a good 10 to 15 minutes every 30 seconds or so with the intensity varying as the location of the flashes continued to move in a easterly direction.I went in and got my wife and she also observed the light. She wondered if it could have been the ISS and almost on queue the ISS came into view in the western sky moving north/northeast.We live in the flight path of Newark and JFK airports so jets in our night sky are an common thing but this was different than any plane/jet I've ever seen. I'm also an amateur astronomer and have been for over 40 years and have seen everything from bolide meteors, satellites, all the naked eye planets, auroras, comets and to many other astronomical items to list but what I saw last night baffles me. I'm not saying this was UFO but it was something I've never seen before in the night sky. Would like to know else in my area that might have noticed this phenomenon.