NGC 246
Planetary Nebula in Cetus
| Position (J2000): | 00h47m03s -11°52'20" |
| Magnitude: | 10.9 |
| Size: | 4'.6 x 4'.1 |
| Class: | 3b |
| Finder Charts: | 30° | 15° | 5° |
| Search Radius: | 5° |
| NGC Description: | vF, L, 4 st in dif neb |
| Other Identifiers: | Caldwell 56 (C 56), PK118-74.1, H V-25, h 56, GC 131, PN G118.8-74.7, HIP 3678 |
Discovered in 1785 by William Herschel, NGC 246 is a relatively large planetary nebula. The central star of this nebula (HIP 3678) is actually two stars close in angular separation (3.8" distant at PA 129°). These stars are most likely line-of-sight, but the pair could be a binary star system. The central star is responsible for creating the nebula as it puffs it's outer layers out into space. As measured by HIPPARCOS, the distance to this star system is 2100 light years, which implies an actual size of 6 light years for the surrounding nebulosity. That's one and a half times the distance from our sun to the nearest star. There are two other 11th magnitude stars that lie within its glow. These are probably foreground or background stars not associated with the nebula.
Although visible to a trained observer under dark skies in telescopes as small as 4 inches, most observers will require at least a 6 inch telescope to see its faint, diffuse glow.
Learn more about NGC 246 on the web, browse the observing lists containing NGC 246, or review the references used to gather information regarding NGC 246.
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Images
Observations
| ID | Description |
|---|---|
| 1359 | Twin Lakes Star Party 2005 - October 3, 2005 04:33 UT At 159x with the 13mm eyepiece in the 406mm reflector and the OIII filter, NGC 246 (Caldwell 56) appears as a bright, large, round, diffuse ball of nebulosity surrounding three bright field stars. The nebulosity is much dimmer on the eastern edge and subtle shading and dark lanes are visible across the surface. |
| 707 | First light for the 35mm Panoptic - December 1, 2002 03:04 UT At 111x with the 18mm eyepiece in the 203mm SCT, NGC246 appears as a very, very faint, large, oval-shaped glow surrounding a diamond-shaped set of faint field stars. The glow is only detectable with averted vision. Some variations in the brightness of the glow are detectable and one side is darker than the other is. |
