About NGC 1931
NGC 1931 is a common cluster. It sits in the constellation Aur and shines at apparent magnitude 10.1.
A star cluster still wrapped in the nebula that made it — newborn stars lighting up their own birth cloud.
Common cluster 19 EP
NGC 1931
RA 82.8556° · Dec 34.2466° · openngc
Score breakdown
· 2 badgesCommon 22 pts → Uncommon
- Cluster still wrapped in its gas +12
- Star cluster +7
Total score 19
3 more points to reach Uncommon.
Badges
- Star cluster · +7
- Cluster still wrapped in its gas · +12
Trivia
What it actually is
- What it actually is. A star cluster still wrapped in the nebula that made it — newborn stars lighting up their own birth cloud.
Find it in the sky
- How to spot it. At magnitude 10.1 you'll want a small backyard telescope, over in Auriga.
- Northern sky. It rides the northern half of the sky — an easier target the further north you are.
- Best time of year. It stands highest in the middle of the night around December — that's when to go looking.
Its true colour
- Its true colour. The stars are blue-white and brand new; the gas around them glows red, ionised by their ultraviolet glare.
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
- Aur
- dso type
- Cl+N
- mag
- 10.1
- name
- NGC 1931
- size arcmin
- 4.8
How to see it
Look for NGC 1931 in the constellation Aur. At apparent magnitude 10.1, a small backyard telescope will bring it into view.
Like any astronomical target, NGC 1931 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 1931 is a common cluster
NGC 1931 scores 19 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 2 science badges — Star cluster and Cluster still wrapped in its gas — 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.