NGC 1891 is an open star cluster located in the constellation of Auriga. It was discovered by the astronomer William Herschel in 1786. The cluster is approximately 12,000 light-years away from Earth and contains several young stars that are still in the process of forming. The cluster spans about 10 light-years in diameter and is estimated to be around 100 million years old. NGC 1891 is not as well-known as some other star clusters, but it provides valuable insights into the formation and evolution of stars in our galaxy, the Milky Way.