Light quickly grows in intensity and then fades to nothing.

I went outside to feed my dog.  I normally spend a few minutes looking at the stars and observing; looking at constellations, spotting satellites, etc.
As I glanced over the sky to my north, I noticed a "star" that I didn't recognize.  I shrugged it off as being an airplane and figured I'd look again in a minute to see if it was still there.  As I looked a little to the east, and north of the light (towards the big dipper), I saw the light get very bright out of the corner of my eye.  I looked towards the direction of the light, and over the course of maybe 2 seconds the light grew very bright, brighter than Venus on comparison, and then quickly faded away to nothing.  I could not tell if this was an object that appeared bright as it come closer to me and dim as it went away, or if the object was in fact getting brighter and then faded to nothing.   If the object was in motion, it would have been vastly quicker in speed than any conventional aircraft.  There were no sounds associated with this event.