slowly flashing "star" in the sky?

This morning about 6:00AM I was outside and looking South , up maybe 30-40 degrees from the Horizon I saw what looked like a star, only it was flashing on about every 4-10 seconds for about 2 seconds, then it would go out. It flashed about eight-10 times then stopped and I never saw it again.

This was stationary- it never moved from the spot I saw it so it was not an airplane. It went completely OFF for 5-10 seconds at a time, so it was not a pulsar or star being seen through atmospheric weirdness. There were no clouds (no other stars flashing)

I tried looking this type of thing up on google but only found descriptions of pulsars which "shimmer" not flash on and off.

I have seen satellites fly over before, and it was not a satellite (maybe geosynchronous though?)

The closest thing I could find is a "solar sail" which is a new thing NASA put up I think, it "flashes" as it tumbles end over end in Space, but it MOVEs- not stationary.

Obviously its not a UFO cause it didn't FLY. (unidentified flying object)

Anyone have any idea?