About Coalsack Cluster
Coalsack Cluster is a common cluster. It sits in the constellation Cru and shines at apparent magnitude 6.9.
Notable enough to have earned a proper name, not just a catalogue number.
Common cluster 21 EP
Coalsack Cluster
RA 190.5701° · Dec -62.9958° · openngc
Score breakdown
· 3 badgesCommon 24 pts → Uncommon
- Has a proper name +8
- Star cluster +7
- Bright deep-sky object +6
Total score 21
3 more points to reach Uncommon.
Badges
- Star cluster · +7
- Bright deep-sky object · +6
- Has a proper name · +8
Trivia
How we found it
- Named. Notable enough to have earned a proper name, not just a catalogue number.
Properties
- constellation
- Cru
- dso type
- OCl
- mag
- 6.9
- name
- Coalsack Cluster
- named
- yes
How to see it
Look for Coalsack Cluster in the constellation Cru. At apparent magnitude 6.9, it is an easy target for binoculars.
Like any astronomical target, Coalsack 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.
Why Coalsack Cluster is a common cluster
Coalsack Cluster scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.
That score comes from 3 science badges — Star cluster, Bright deep-sky object and Has a proper name — 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.