About NGC 281
NGC 281 is a rare nebula. It sits in the constellation Cas.
An H II region: a cloud of hydrogen being ionised by the ultraviolet flood from hot young stars inside it. Every one is a star factory caught mid-production.
Rare nebula 48 EP
NGC 281
RA 13.2473° · Dec 56.6219° · openngc
Score breakdown
· 5 badgesRare 50 pts → Epic
- Star-forming region +14
- Bigger on the sky than the full Moon +12
- Coming towards us +10
- Nebula +8
- Never sets (northern circumpolar) +4
Total score 48
2 more points to reach Epic.
Badges
- Nebula · +8
- Star-forming region · +14
- Never sets (northern circumpolar) · +4
- Bigger on the sky than the full Moon · +12
- Coming towards us · +10
Trivia
What it actually is
- What it actually is. An H II region: a cloud of hydrogen being ionised by the ultraviolet flood from hot young stars inside it. Every one is a star factory caught mid-production.
Find it in the sky
- Where to look. You'll find it in the constellation Cassiopeia.
- 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 October — that's when to go looking.
Its true colour
- Its true colour. That signature crimson is hydrogen-alpha at 656 nanometres — electrons falling back onto protons, one photon at a time.
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
- Cas
- dso type
- HII
- name
- NGC 281
- radial velocity kms
- -34
- size arcmin
- 35
How to see it
Look for NGC 281 in the constellation Cas.
Like any astronomical target, NGC 281 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 281 is a rare nebula
NGC 281 scores 48 points on Spacedle's rarity scale, which places it in the rare tier. Another 2 points would lift it into a rarer tier.
That score comes from 5 science badges — Nebula, Star-forming region, Never sets (northern circumpolar), Bigger on the sky than the full Moon and Coming towards us — 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.