RA 268.4632° · Dec -34.7928° · openngc
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10 more points to reach Anomaly.
Ptolemy's Cluster is an epic cluster. It lies about 913.5 light-years from Earth, sits in the constellation Sco and shines at apparent magnitude 3.3.
An open cluster: a few hundred stars born together out of one collapsing cloud, still drifting along in loose formation.
Look for Ptolemy's Cluster in the constellation Sco. At apparent magnitude 3.3, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, Ptolemy's Cluster 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.
Ptolemy's Cluster scores 68 points on Spacedle's rarity scale, which places it in the epic tier. Another 10 points would lift it into a rarer tier.
That score comes from 9 science badges — Star cluster, Messier object, Bright deep-sky object, Has a proper name, Open cluster, On the zodiac, Big on the sky 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.