Watching the stars move

While lying on my side in bed at night I can see out of the top half of one of our bedroom windows. It faces the northeast. Last night at 2:10 am I noticed two bright stars, on above the other (not quite directly above, but a little to the right), about (what appeared to my eyes) 3/4 inch apart, if I held my fingers up to it about three inches from my eyes. A few minutes later a third fainter star appeared from the top of the left side of the window. A beautiful triangle.

I watched the star triangle move, upwards and to the right, slowly. A slow, quiet drama. I couldn't go back to sleep for watching it, visually trying to calculate the exact angle the triangle was moving. At 2:59 the upper right star of the triangle finally disappeared behind the top of the window frame. An impressive disappearance, and satisfying to observe. The triangle was gone.

Somewhat later I returned to sleep.