About Rosette A
Rosette A is a rare nebula. It sits in the constellation Mon.
A nebula: a cloud of interstellar gas and dust, thinner than the best vacuum ever made in a laboratory yet spanning light-years.
Rare nebula 34 EP
Rosette A
RA 97.7275° · Dec 5.0492° · openngc
Score breakdown
· 4 badgesRare 50 pts → Epic
- Bigger on the sky than the full Moon +12
- Nebula +8
- Has a proper name +8
- Diffuse nebula +6
Total score 34
16 more points to reach Epic.
Badges
- Nebula · +8
- Has a proper name · +8
- Diffuse nebula · +6
- Bigger on the sky than the full Moon · +12
Trivia
What it actually is
- What it actually is. A nebula: a cloud of interstellar gas and dust, thinner than the best vacuum ever made in a laboratory yet spanning light-years.
Find it in the sky
- Where to look. You'll find it in the constellation Monoceros.
- 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 December — that's when to go looking.
Its true colour
- Its true colour. Nebular colours are chemistry made visible — red for hydrogen, teal for oxygen, blue where starlight is merely scattered.
What's in a name
- Named. Notable enough to have earned a proper name, not just a catalogue number.
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
- Mon
- dso type
- Neb
- name
- Rosette A
- named
- yes
- radial velocity kms
- 38
- redshift
- 0.0001
- size arcmin
- 80
How to see it
Look for Rosette A in the constellation Mon.
Like any astronomical target, Rosette A 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 Rosette A is a rare nebula
Rosette A scores 34 points on Spacedle's rarity scale, which places it in the rare tier. Another 16 points would lift it into a rarer tier.
That score comes from 4 science badges — Nebula, Has a proper name, Diffuse nebula and Bigger on the sky than the full Moon — 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.