I would not have seen this if not already looking up at stars. Said to my wife "that's crazy... what is that?", by the time she moved to my side of the hot tub it was moving past a tree. I pointed but like I said, you almost had to be looking directly at the sky where it passed to notice it, so she didn't catch it. At first it reminded me of a glowing string, but very uniformed, and in hind sight I'd say it was about like the leading edge of a boomerang. Maybe like something (shooting star?) had shot through the sky and left a trail, curved, somewhat dimmer than the light of the stars next to it. Easy to miss if you weren't looking.Then, I realized it was moving, and fast. And totally quiet. And it wasn't moving the direction I'd have guessed, because my initial take of "shooting star leaving a trail" wasn't right. It was moving as if flying, all the sudden it reminded me of the leading edge of a b2 bomber, but smoother curve. There was trajectory and symmetry. It was headed the direction the nose was facing. There was a sense of mass or something behind the illuminated edge.I wish I had the sense to track stars it was passing before they passed to see if it was blocking them, and for how long, I felt it had some mass behind the leading edge glow, but I didn't prove it to myself as I watched it by checking for stars it was about to pass. Wish I'd thought of that.In the 40 seconds I watched (maybe 20 seconds, no clue on time), it seemed boomerang shaped but other than my impression, I only know for sure the front edge was. The rest was dark/transparent. No lights other than the leading edge glow.And it moved in a direction, pretty fast (I live and work next to an airport (OKC)), I know how fast airplanes cover the skyline, this was faster, high, and biger. And quiet. But not knowing what I was looking at, hard to put in perspective.It went over the tree, past the next house, and I saw nothing else. Never seen anything like it before. Totally quiet.