Catalogue and alternative designations NGC 6397   Type Globular Cluster  Position  17 40.7, -53 40 Constellation Ara Camera and Telescope STL11000M and 31.75 cm Ritchey Chretien Focal Ratio F9 Exposure Details LRGB =80:75:60:75 with Astrodon filters all 1x1 Description NGC 6397 is the seventh  brightest globular in the sky and the second nearest after M4.  It is a very effective object in small apertures because the component stars are generally brighter than many other bright globulars.