NGC 6791 is an open star cluster in the Lyra constellation.It was discovered by Friedrich August Theodor Winnecke in 1853. At roughly 8 billion years old, and with an Iron to Hydrogen abundance ratio that is more than twice that of the Sun, it is one of the oldest and most metal-rich clusters in the Milky Way. This is contrary to the typical rule-of-thumb where older means more metal-poor. Compounded with the fact that it has an unusually high population of stars, NGC 6791 is among the most studied clusters in the sky.
A single shoot image, 20 minutes bin 2 without any filter, uncalibrated, a bit processed in Pixinsight.