Messier 103 and Trumpler 1
There are about 40 members stars in Messier 103 (M103), one of the most distant of the Messier open clusters, it is about 9,000 light years away (upper right corner of my image). The brightest star in the open cluster is actually not a part of it, it is the binary star system called Struve 131 and just happens to be between us and M103. The two brightest member stars in this open cluster are magnitude 10.5 and 10.8 including a red giant in the central portion of the cluster. The age of this cluster is estimated to be 9 to 25 million years old. In the lower left corner is the open cluster Trumpler 1, named after Robert Trumpler who completed a study of open clusters in 1930 including 37 new clusters (Trumpler clusters).
Tech Specs: Sky-Watcher Esprit 120mm ED Triplet APO Refractor, Celestron CGEM-DX mount, Canon 6D stock camera, ISO 3200, 15 x 60 second exposures with dark/bias frames, guided using a ZWO ASI290MC and Orion 60mm guide scope. Image date: September 28, 2018. Location: The Dark Side Observatory, Weatherly, PA, USA.