M75 is a globular cluster in Sagittarius lying at a distance of 67,500 light-years. This means when we view M75, we are peering past the south side of the Milky Way galaxy’s core and seeing this globular cluster hovering over the outskirts of the far side of our galaxy’s disk. Harlow Shapley and Helen Sawyer classified globular clusters on a scale of I-XII based on how densely packed they are. Class I globulars are so densely packed as to have unresolvable cores, whereas class XII are so loosely packed as to resemble circular open star clusters. M75 is the only Class I globular in the Messier Catalog and is notorious for being so densely packed as to be unresolvable through even the largest amateur telescopes. However, photographically, the CDK17 resolved the core of this globular cluster spectacularly well.

Telescope/Mount: PlaneWave CDK17 on L500 mount.

Exposures: L:R:G:B = 165:60:60:60 minutes = 5 hours, 40 minutes total exposure at f/6.8.