| The Skull Nebula: Planetary Nebula NGC 246 |
NGC 246 is a dim planetary nebula in the constellation Cetus the whale, at a distance reported between 1,600 and 2,100 light-years.
Although it is much larger than other better known planetary nebula such as the Ring Nebula, it is low in the sky for northern observers,
and relatively dim, so it gets much less attention. Like other planetary nebula, NGC 246 is a dying star that over thousands of years
has shed its outer atmosphere, of blue-green oxygen and red hydrogen, illuminated by the glowing white-hot ember of its fading central
star.
An Astronomy "Picture of the Day" in April 2006, taken with the Gemini South Telescope, describes NGC246 as the "Skull Nebula".
Discovered in 1785 by William Herschel, NGC 246 is a relatively large planetary nebula. The central star of this nebula is actually two
stars too close in angular separation (3.8") to be separated by my image. These stars are most likely line-of-sight, but the pair could be
a binary star system. NGC 246 has recently been catalogued as Caldwell 56.
This image combined 75 minutes of unbinned luminance exposures with a clear filter with 45 minutes of red, 40 minutes of green, and
60 minutes of blue exposures. An ST10XME camera was used through a Meade 12" LX200R telescope with an AP 0.67x
nosepiece reducer. For a wider field that includes a nearby galaxy, click here.
Although it is much larger than other better known planetary nebula such as the Ring Nebula, it is low in the sky for northern observers,
and relatively dim, so it gets much less attention. Like other planetary nebula, NGC 246 is a dying star that over thousands of years
has shed its outer atmosphere, of blue-green oxygen and red hydrogen, illuminated by the glowing white-hot ember of its fading central
star.
An Astronomy "Picture of the Day" in April 2006, taken with the Gemini South Telescope, describes NGC246 as the "Skull Nebula".
Discovered in 1785 by William Herschel, NGC 246 is a relatively large planetary nebula. The central star of this nebula is actually two
stars too close in angular separation (3.8") to be separated by my image. These stars are most likely line-of-sight, but the pair could be
a binary star system. NGC 246 has recently been catalogued as Caldwell 56.
This image combined 75 minutes of unbinned luminance exposures with a clear filter with 45 minutes of red, 40 minutes of green, and
60 minutes of blue exposures. An ST10XME camera was used through a Meade 12" LX200R telescope with an AP 0.67x
nosepiece reducer. For a wider field that includes a nearby galaxy, click here.
Music: Monster Mash
