RA 272.5766° · Dec -31.7635° · openngc
8 more points to reach Epic.
NGC 6558 is a rare cluster. It sits in the constellation Sgr and shines at apparent magnitude 11.29.
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 6558 in the constellation Sgr. At apparent magnitude 11.29, a small backyard telescope will bring it into view.
Like any astronomical target, NGC 6558 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 6558 scores 42 points on Spacedle's rarity scale, which places it in the rare tier. Another 8 points would lift it into a rarer tier.
That score comes from 5 science badges — Star cluster, Globular cluster, Toward the galactic centre, On the zodiac and Coming towards us — 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.