NGC 6791 is an open star cluster located in the constellation of Lyra. It is approximately 13 billion years old, making it one of the oldest known star clusters in our galaxy. NGC 6791 contains a rich population of stars, including many red giants and a significant number of binary star systems. The cluster is situated about 2,500 light-years away from Earth and spans roughly 80 light-years in diameter. Its high metallicity suggests that it formed in a region with abundant heavy elements, which is unusual for such an old cluster. NGC 6791 is often studied to understand stellar evolution and the history of the Milky Way.