It was after a ufo conference in Toronto. I drove guest home to where they had reported to me sightings of strange lights traversing the sky in the previous nights. On arriving at her place of residency I was taken to the back yard. Within 5 minutes a bright large white light appeared in the night sky round in appearance. It increased in brightness until it almost reached the brightness of a welders arc. The time of exposure was 4 seconds before it just went out much like someone had turned a light switch off only to reappear again with half it's original brightness, and lasting another 4 seconds. This pulsating action continued for about 30 seconds as the object moved away from us. At arms length the object was the size of a silver dollar. The following evening, Michelle reported to me an illuminated orb flying high over her head as she was letting the cat out. It was explained to me that the object did a "power up" followed by another bright light that crossed the sky at a fast pace.