RA 122.6541° · Dec -12.8207° · openngc
7 more points to reach Rare.
NGC 2539 is an uncommon cluster. It lies about 4,325.7 light-years from Earth, sits in the constellation Pup and shines at apparent magnitude 6.5.
An open cluster: a few hundred stars born together out of one collapsing cloud, still drifting along in loose formation.
Look for NGC 2539 in the constellation Pup. At apparent magnitude 6.5, it is an easy target for binoculars.
Like any astronomical target, NGC 2539 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 2539 scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.
That score comes from 5 science badges — Star cluster, Distant (over 1,000 light-years), Bright deep-sky object, Open 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.