About IC 3555
IC 3555 is an uncommon nebula. It sits in the constellation Com.
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.
Uncommon nebula 22 EP
IC 3555
RA 188.9831° · Dec 27.9889° · openngc
Score breakdown
· 2 badgesUncommon 34 pts → Rare
- Star-forming region +14
- Nebula +8
Total score 22
12 more points to reach Rare.
Badges
- Nebula · +8
- Star-forming region · +14
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 Coma Berenices.
- 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 March — 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 Index Catalogue. The IC was the 1895 and 1908 supplement to the NGC — the first catalogue in history to be filled largely with objects found on photographic plates rather than by eye.
Properties
- constellation
- Com
- dso type
- HII
- name
- IC 3555
Nearby objects
How to see it
Look for IC 3555 in the constellation Com.
Like any astronomical target, IC 3555 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 IC 3555 is an uncommon nebula
IC 3555 scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 points would lift it into a rarer tier.
That score comes from 2 science badges — Nebula and Star-forming region — 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.