NGC 6397, also known as Caldwell 86, is a globular cluster in the constellation Ara. It is located about 7,800 light-years from Earth, making it one of the two nearest globular clusters to Earth. The cluster contains around 400,000 stars, and can be seen with the naked eye under good observing conditions.

Distance: 7.8 kly (2.4 kpc)

Apparent magnitude (V): +6.68

Apparent dimensions (V): 32′.0

Constellation: Ara

Metallicity: = –1.76 dex

Notable features: Second closest globular to Earth