Aha! I finally managed to catch one open!

The lovely moonflower vine opens at dusk and closes shortly after daylight.
This makes it pretty hard for those of us who are not too fond of going outside after dark or before dawn to capture a picture of it.

I have seen several brown shriveled up flowers, but today I caught one fully open.

My vine has lots more buds, so I hope the frost holds off for a few more days.