During a time when commercial aircraft are grounded, a large Triangle shaped UFO was reported moving from north, curving to the south-east, seemingly following the Ompompanoosuc river. The UFO Sighting was accompanied by an engine sound so I first assumed it was a plane from the post mills airport. However, after observing it move overhead I realized I couldn't see any green navigation lights or the regular strobe lights seen on an airplane. The UFO Sighting consisted of three or four small white lights in the shape of a triangle. the center was a proportionally larger red light which flashed on and off with about a 1 to 2 second fade. The UFO sounded unlike any prop or jet engine I have heard. Typically you hear a change in pitch change from Doppler affect as the craft moves overhead, but this UFO seemed unchanging. MUFON CMS# 107486 Thetford Vermont US, Region has had 251 Reported UFO Sightings to date.