About NGC 2242
NGC 2242 is a rare nebula. It sits in the constellation Aur and shines at apparent magnitude 15.
A planetary nebula: the shed outer atmosphere of a dying Sun-like star, lit from within by the naked stellar core left behind.
Rare nebula 35 EP
NGC 2242
RA 98.5302° · Dec 44.7770° · openngc
Score breakdown
· 4 badgesRare 50 pts → Epic
- Planetary nebula (a dying star's shell) +12
- Its dying star is still visible +12
- Nebula +8
- Faint fuzzy (mag > 13) +3
Total score 35
15 more points to reach Epic.
Badges
- Nebula · +8
- Planetary nebula (a dying star's shell) · +12
- Its dying star is still visible · +12
- Faint fuzzy (mag > 13) · +3
Trivia
What it actually is
- What it actually is. A planetary nebula: the shed outer atmosphere of a dying Sun-like star, lit from within by the naked stellar core left behind.
Find it in the sky
- How to spot it. At magnitude 15 it is far too faint for the eye: this one belongs to cameras and long exposures, 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. Its teal-green comes from doubly-ionised oxygen at 501 nanometres, and its red from hydrogen at 656 — colours no ordinary object on Earth produces.
What's in a name
- A misleading name. 'Planetary nebula' is a 240-year-old mistake. William Herschel coined it in the 1780s because these round greenish discs resembled the planet Uranus he had just discovered. There are no planets involved whatsoever.
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
- central star mag
- 17.6
- constellation
- Aur
- dso type
- PN
- mag
- 15
- name
- NGC 2242
- radial velocity kms
- 38
- redshift
- 0.0001
- size arcmin
- 0.45
How to see it
Look for NGC 2242 in the constellation Aur. At apparent magnitude 15, it takes a larger telescope or a long-exposure image to capture.
Like any astronomical target, NGC 2242 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 2242 is a rare nebula
NGC 2242 scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.
That score comes from 4 science badges — Nebula, Planetary nebula (a dying star's shell), Its dying star is still visible and Faint fuzzy (mag > 13) — 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.