My girlfriend decided to go out to Millenium Park in Dorval, QC. It's a nice park with a open area where you can sit and star gaze. My girlfriend placed the bed sheets and blanket that she brought with her right in the middle of the park. The moon was very bright and the sky was semi-polluted where you can still see the stars, but the sky wasn't pitch black.About 20 minutes of star gazing, my girlfriend pointed towards the south and said "Hey look, what is that?". I quickly looked where she was pointing only to see a very distinctive circular object. The UFO had a grey base which matched the color of the polluted sky, but it also had a "flaming" orange color on the outer edges all around. What was particularly strange about this UFO is that it was gliding, made no sound, and would change speeds. The UFO was slow from the beginning, but started to gain burst of speeds every second. It wasn't a constant speed which was strange.There were plenty of planes flying around with big flashy lights and going at the same speed. The object we witnessed was going slower than the planes we were looking, but has a very distinctive oval shape, and had an orange/flaming ring on the outside which definitely distinguished itself from any plane we saw. The UFO eventually glided out of site and that was the last we saw of it.