NGC 6440 & NGC 6540 -- Globular Clusters in Sagittarius
The Realm of the Globular Clusters
Globular Clusters are concentrated towards the core of our galaxy. The constellations of
Scorpius (the Scorpion), Sagittarius (the Archer) and Ophiuchus (the Serpent Bearer) are
speckled with them. These tight spheres of tens-of-thousands of stars are extremely old.
Their relationship with our galaxy is complex, some appear to be old cores from dwarf
galaxies cannibalized by our much larger Milky Way galaxy, while others appear to have
formed within our galaxy or possibly predate the galaxy itself.
NGC 6540 was just a wisp in my small refractor, showing no structure and appearing like a
faint comet. NGC 6440 appeared more condensed and looked more like what it was, a