Silent, triangular flying object with a row of 4 dimly-lit lights straight down the underside moving at a slow-medium rate of speed

I was on the street around 8:10 PM when I saw/heard a helicopter above. I looked up at the sky and then noticed around 4 dim lights in a row/straight line moving at a slow-medium rate of speed overhead to the left of where the helicopter had passed by. The helicopter had since passed at this point. I realized that the lights were on the underside of a triangular flying object that blended into the sky. I would estimate that the object was larger than a passenger plane. The flying object almost seemed to be translucent or camoflauged and was moving discretely. I would not have noticed it had it not been for the lights underneath. The sky was relatively clear - there was some clouds but overall it was clear and easy to see the stars. The flying object was higher than a helicopter but lower than a plane. The lights were dim - not as bright as lights on planes - and a white/light yellow color. I did not hear it emit any noise. It seemed as if it was just leisurely gliding through the sky and did not want to be detected.