Celestial hemisphere:  Southern  ·  Constellation: Cetus (Cet)  ·  Contains:  NGC 246  ·  NGC 255  ·  PK118-74.1
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NGC 246 the Skull Nebula, 


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NGC 246 the Skull Nebula

Getting plate-solving status, please wait...
NGC 246 the Skull Nebula, 


Powered byPixInsight

NGC 246 the Skull Nebula

Acquisition details

Oct. 20, 2021 ·  Oct. 21, 2021 ·  Oct. 22, 2021 ·  Oct. 25, 2021 ·  Oct. 27, 2021 ·  Oct. 29, 2021 ·  Oct. 31, 2021
Chroma Technology Chroma Blue: 28×300(2h 20′) bin 1×1
Chroma Technology Chroma Green: 28×300(2h 20′) bin 1×1
Chroma Technology Chroma Ha 3nm: 28×1200(9h 20′) bin 1×1
Chroma Technology Chroma OIII 3nm: 30×1200(10h) bin 1×1
Chroma Technology Chroma SII 3nm: 10×1200(3h 20′) bin 1×1
Chroma L: 95×300(7h 55′) -20°C bin 1×1
Chroma Red: 28×300(2h 20′) -20°C bin 1×1
37h 35′
Avg. Moon age:
19.18 days
Avg. Moon phase:
Bortle Dark-Sky Scale:

RA center: 00h47m12s.894

DEC center: -11°4616.97

Pixel scale: 0.732 arcsec/pixel

Orientation: 0.820 degrees

Field radius: 0.554 degrees

WCS transformation: thin plate spline

More info:Open 

Resolution: 4068x3636

File size: 84.7 MB

Data source: Own remote observatory

Remote source: Observatorio El Sauce



the image published today is a planetary nebula: NGC 246, also called the Skull Nebula. It is to be found in the Whale (Cetus). The nebula, of magnitude 10, is located 1,600 light-years from Earth.This ethereal remnant of a long-dead star, nestled in the belly of The Whale, hardly resembles a skull floating in space. This planetary nebula is the first known to be associated with a pair of closely related stars orbited by a third outer star.This star, which is not visible in this image, is a dark red dwarf that lies near the white dwarf at about 500 times the distance between the Earth and the Sun. The red and white dwarf stars orbit each other in pairs, and the outer star orbits the two dwarfs at a distance of about 1900 times the Earth-Sun separation. Collectively, these three stars establish NGC 246 as the first known planetary nebula with a triple-hierarchical star system at its center.This image of the Skull Nebula intentionally captures light emitted in certain narrow ranges of wavelengths – those associated with hydrogen and oxygen gas. Observations of the light emitted by particular elements help reveal a wealth of information about the chemical and structural compositions of an object. This new image of the Skull Nebula highlights where NGC 246 is rich or poor in hydrogen (in red) and oxygen (shown in light blue).The complex braided structure of NGC 246's blue outer ring, visible in this image taken by the Gemini South Telescope, is thought to result from the action of shock waves. As the compressed outer shell stacks against the interstellar medium, it heats up and becomes unstable, fragmenting it. High-speed gases pushing outward from the hot central star (~200,000 K) can also contribute to visible chaos. Collisions between these fast winds and the shocked shell could explain the distinctive green lobes and darker voids visible in the main half of NGC 246's inner hull.     The uneven expansion along the main axis of the nebula results in visible asymmetry: as shown in the image here, the outer structure of NGC 246 has the shape of an oval ring. Its leading edge (upper) appears brighter and sharper than its leading edge (lower). The central binary star is slightly moved to the leading edge of the shell, as astronomers had predicted.The nebula is relatively small and dark (magnitude 11). On this image we can also note 3 galaxies:•        NGC 255 (top left) a barred spiral galaxy SBc of mag 12.5 at about 71 million AL.•        MCG-02-03-009: (top right) a dwarf galaxy of magnitude 14•        MCG-02-03-020: (left) a small galaxy of type LSB_G of mag 15By searching well we can find some galaxies from the APMUKS catalog that are very distant galaxies and of which we have very little information, apart from their magnitude.The image is an L Rha-GOIII-BOIII at about 70% for RGB, the SII signal is practically non-existent.


Sky plot

Sky plot


NGC 246 the Skull Nebula,