Caldwell 39 — Planetary Nebula in Gemini
NGC 2392
About Eskimo Nebula
Description
The Eskimo Nebula (NGC 2392) is a planetary nebula in Gemini, about 6,500 light-years away. In telescopes, it shows a bright central disk surrounded by a fainter outer shell, which together resemble a face surrounded by a fur-lined parka hood.
Observing Tips
One of the brightest and most rewarding planetary nebulae. A 4-inch telescope easily shows the bright disk. At 150x+ in an 8-inch scope, the double-shell structure becomes visible. An OIII filter helps with the outer shell. Best in winter and spring evenings.
History
Discovered by William Herschel on January 17, 1787. The Hubble Space Telescope revealed intricate radial filaments in the outer shell that gave the "fur hood" its texture.
Fun Facts
The inner shell is expanding at about 90 km/s while the outer shell moves at about 40 km/s, suggesting two separate ejection events. The central star has a surface temperature of 40,000 K.
Observe
1Properties
Position & Identifiers
2How easy to spot?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Medium | Medium | Hard+ |
| 150 mm Newton 150mm Newt. | Medium+ | Medium+ | Medium |
| Celestron C8 (203 mm SCT) C8 203mm | Medium+ | Medium+ | Medium+ |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
With O-III filter
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Easy | Easy | Medium+ |
| 150 mm Newton 150mm Newt. | Easy | Easy | Easy |
| Celestron C8 (203 mm SCT) C8 203mm | Easy | Easy | Easy |
3Visibility
Set a location in User Settings to see visibility data.
4
Filter Response Guide
5
Eyepiece View
6
Best Magnification
Explore
7
Central Star
8
Surface Brightness
Discover
9
Light Travel Time Machine
10
Relativistic Travel
Community Photos (1)
Credit: NASA, ESA, Andrew Fruchter (STScI), and the ERO team (STScI + ST-ECF). License: Public domain. (Wikimedia Commons)
Skybred Mar 2, 2026
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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