About NGC 6539
NGC 6539 is a common cluster. It sits in the constellation Se2.
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.
Common cluster 21 EP
NGC 6539
RA 271.2073° · Dec -7.5859° · openngc
Score breakdown
· 2 badgesCommon 22 pts → Uncommon
- Globular cluster +14
- Star cluster +7
Total score 21
1 more point to reach Uncommon.
Badges
- Star cluster · +7
- Globular cluster · +14
Trivia
What it actually is
- What it actually is. 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.
Sense of scale
- Sense of scale. Stand on a planet near its core and the night sky would blaze with thousands of stars brighter than Venus. There would be no true darkness.
Find it in the sky
- Where to look. You'll find it in the constellation Serpens Cauda.
- Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
- Best time of year. It stands highest in the middle of the night around June — that's when to go looking.
Its true colour
- Its true colour. Globulars glow yellow-orange because they are ancient — around 12 billion years old, with every hot blue star long since burned out.
How we came to know it
- The New General Catalogue. Its NGC number comes from J. L. E. Dreyer's 1888 catalogue, itself built on decades of sky sweeps by William Herschel and his sister Caroline.
Properties
- constellation
- Se2
- dso type
- GCl
- name
- NGC 6539
- radial velocity kms
- 36
- redshift
- 0.0001
- size arcmin
- 6
How to see it
Look for NGC 6539 in the constellation Se2.
Like any astronomical target, NGC 6539 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 NGC 6539 is a common cluster
NGC 6539 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.
That score comes from 2 science badges — Star cluster and Globular cluster — 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.