M15 is one of the most densely packed globular clusters known and might house a black hole at its core. Its 100,000+ stars are among the oldest in the universe. It is about 33,000 light-years away in the constellation Pegasus.
More detail from the same image is shown below. These images are at the same scale as the images of globular clusters M2, M5, M13, M71, and M92.
120 minutes L and 96 minutes RGB binned 2x2 on 2013-10-02 using a QSI 583 from northern New Jersey through an Astro-Physics 155mm refractor at f7.1. North is up. ©2013