47 Tucanae Globular Cluster (NGC 104) Image by Martin_Heigan 47 Tucanae (NGC 104) or 47 Tuc is a Globular Cluster located in the constellation Tucana. It is about 16,700 light-years from Earth, and 120 light years across. It is the second brightest globular cluster in the sky (after Omega Centauri), and is noted for having a very bright and dense core. It is also one of the … [Read more...] about 47 Tucanae Globular Cluster (NGC 104)