Rare cluster 47 EP

NGC 6121

RA 245.8975° · Dec -26.5255° · openngc

Loading sky survey…

🌌 View in 3D star map

Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 6 badges

47 pts · Rare

Rare 50 pts → Epic

Globular cluster +14
Messier object +12
Star cluster +7
Bright deep-sky object +6
Big on the sky +5
On the zodiac +3

Total score 47

3 more points to reach Epic.

Badges

Star cluster · +7
Messier object · +12
Bright deep-sky object · +6
Globular cluster · +14
On the zodiac · +3
Big on the sky · +5

Trivia

Hard to believe

Messier object. One of the 110 showpieces of the Messier list — catalogued as M4.

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

How to spot it. At magnitude 5.4 you can see it with your own eyes from a dark site, over in Scorpius.
Southern sky. It rides the southern half of the sky — an easier target the further south you are.
Best time of year. It stands highest in the middle of the night around May — 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

Messier's anti-list. Charles Messier was a comet hunter, and he compiled his famous catalogue in the 1770s and 80s purely as a list of fuzzy things that are NOT comets. History remembers the distractions and forgets the comets.

Properties

constellation: Sco
dso type: GCl
mag: 5.4
messier: yes
messier number: 004
name: NGC 6121
radial velocity kms: 71
redshift: 0.0002
size arcmin: 28.2

Nearby objects

About NGC 6121

NGC 6121 is a rare cluster. It sits in the constellation Sco and shines at apparent magnitude 5.4.

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.

How to see it

Look for NGC 6121 in the constellation Sco. At apparent magnitude 5.4, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, NGC 6121 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 6121 is a rare cluster

NGC 6121 scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.

That score comes from 6 science badges — Star cluster, Messier object, Bright deep-sky object, Globular cluster, On the zodiac 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.