This is the Crescent Nebula (also known as NGC 6888 and other names). It is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth – so some of the pyramids were being built on earth when the light we see here left the nebula. It is said to be 4.7 million years old, but I don’t think it looks a day for 4 million…. Very faint and not observable with the naked eye.
William Herschel discovered this in 1792.
This is 2:45 hours’ worth of 300 second exposures taken the middle of December.