I was looking out of the south-west facing window of our apartment (near Chauderon, Lausanne) for meteorites (the peak of the Perseid shower was last night). I had been leaning out of the darkened apartment for at least 15 minutes, which overlooks a darkened courtyard, so my eyes had become accustomed to the darkness.At roughly 1:45am, I saw an object moving rapidly on the left side of my field of view, roughly in a southern direction. I thought initially it must be a meteorite which I'd been spotting at the corner of my field of view for the last couple of nights, so turned to focus at it. I was surprised when it didn't disappear before I could focus on it and secondly thought it must be a low flying plane. When focused on it I then noticed it was 3 lights/orbs in a perfect triangle formation, coming to an extended point at the front of the 3 and moving across the sky in a straight line to the west/north west. They were larger than any of the stars in the sky, or meteorites I'd seen, but much duller, almost blurry and of a yellowy-orangey tinge. The lights were constant in their brightness for the entire time and were only just bright enough to see. I watched it go across almost the entirety of the sky visible from my apartment window before it disappeared into cloud above to my right. This took somewhere around 7-8 seconds.It looked as though there was what I can only describe as heat haze around the lights and in between them all. I could not see a distinct outline of an object, but I had the impression it was a triangular black object with the lights being underneath it, rather than right on the extremities of the wings and nose as you would see on an aeroplane. There was a distinct lack of sound as it flew over (I don't really get any city noise at that time where I am), although I could swear I heard a quiet low humming noise, which seemed to linger for a few seconds after it had passed. I couldn't quite work out the perspective as I viewed it and it seemed either very large or very low (or perhaps both). I'd say it looked slightly larger than a passenger jet and like it was flying only a few hundred feet up. My initial thought was that it was following the north edge of Lake Geneva (it would have been over either that or the south side of town), but looking at a map it must have been heading in a north westerly direction the entire time I was viewing it and the lake takes a south-westerly turn on the West side of Lausanne.My reaction from about halfway through the sighting was for every hair on my body to stand on end. I felt shocked and after losing sight of it woke my fiance up to tell her, but she hugged me while half asleep and fell asleep again. That made me calm down a bit, but I then wrote my account down and told a friend on the internet. At about 2:15pm I went back to the window to watch out for lights rather than the meteorites which I'd now lost interest in and downloaded an app to enhance nighttime filming on my phone. I stood with my camera ready for the next 45 minutes or so taking some practice videos, but saw nothing more than a few more meteorites. The cloud cover had increased greatly by this point too, as only about 25% of the sky was visible, whereas it was more like 80-90% when I saw the lights.