It was probably a piece of space junk or a small meteorite. Stars take years upon years to go supernova then fade from sight. What you saw sounds very cool though.
In my case there is no way it was anything but a star. I was staring directly at it for a few minutes before it went. It was not moving and was definitely a star. I would nightly go out in the hot tub and watch comets, satellites, and other things in the night sky. In fact I use to track the orbiting satellites and be able to name them as they flew overhead by reading the computer schedules. Only other thing it could have been would be a motionless alien spaceship that exploded.
