Delta shaped Craft with four lights that hovered in the sky for 30 seconds and immediately flew away.

Object had a white light at each corner of the delta and one in its exact center. It was stationary above my wife, son, and I who were stargazing. It was the relative size of a quarter given the objects altitude. About 30 seconds after we all saw it, the object accelerated and flew away at an extremely high rate of speed without making a sound or leaving a trail. My blue heeler also was barked and snarled at the object.