Dark Red Sharks Tooth shaped UFO over Hyannis. Flew across night sky in 5 secondsOn the night of June 1, 2016, I was walking out of an appointment and like usual, I looked up at the beautiful Cape Cod sky peppered with thousands and thousands of stars. Then 2 things caught my eye, an airplane (most likely a Cessna 402 ) and a dark red light in the shape of a Sharks Tooth with a single white light in the center. The Airplane and UFO were in the same vicinity for about 15 seconds…it almost seemed like the Sharks Tooth was following the aircraft. So the plane was approx. 2-3000 ft and climbing, whilst the Triangle was maybe 2-300 feet below the Airplane. The Sharks Tooth suddenly accelerated and as the Twin Propeller airplane was climbing slowly, the Dark Red Triangle went from my 5 o’clock (counterclockwise) to my 10 o’clock in about 5 seconds and just disappeared into the early summer night. And just like that it was gone, but that plane was still climbing, it was kind of funny. So the craft was a triangle shape, but with long-sides ( k! inda like a sharks tooth). I think I was lucky in that I had a reference in the airplane, I can 100% say that it was not an airplane.