Witnesses 1,200 Miles Apart Describe Same Giant Triangle UFO

I made a crude gif in an attempt to convey what I saw in '86 (black triangular object) here

I was looking for Halley's comet with a clear sky and just happened to notice a star to the north 'black out' for a few seconds, then another south of that location and so on. The shape only became evident as it crossed the bright band of the Milky Way.

The search for any info on this is what brought me to ATS and all I've found is that there are a lot of us who remain puzzled about these things.