RA 265.1723° · Dec -53.6737° · openngc
2 more points to reach Rare.
NGC 6397 is an uncommon cluster. It sits in the constellation Ara and shines at apparent magnitude 5.17.
A globular cluster: hundreds of thousands of stars packed into a ball a few dozen light-years across, orbiting far out in the galaxy's halo.
Look for NGC 6397 in the constellation Ara. At apparent magnitude 5.17, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, NGC 6397 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
NGC 6397 scores 32 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 2 points would lift it into a rarer tier.
That score comes from 4 science badges — Star cluster, Bright deep-sky object, Globular cluster and Big on the sky — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.