Observations of NGC246
These are the observations available for NGC246. If you have any of your own that you'd like to submit we'd love to put them on the website.
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The Skull Nebula (NGC 246) in Cetus
I've always considered the Skull Nebula to be too low in the sky, with a maximum altitude of just 26 degrees from my location, to image successfully. However, clear skies on the nights of 30th and 31st October gave me an opportunity to attempt it.
NGC 246 is a planetary nebula in the constellation of Cetus and was discovered by William Herschel in 1785. Stephen O'Meara writes about it in his book Deep Sky Companions: The Caldwell Objects and discusses the visibility of the central 12th magnitude star. It turns out that this star is readily visible in my image but it is not the dwarf star responsible for the nebula. The central star is, in fact, at least a triple system. There is a 14 magnitude companion, an orange dwarf star, type G8-K0 V, just 3.8" from the primary. Further, in this link to Stars and Skulls: new ESO image reveals eerie nebula, ESO describes work by the ESO VLT in 2014 that reveals a third red dwarf star.
This image of the Skull Nebula (NGC 246) in Cetus was processed and cropped to show off the nebula by David Davies and taken from Cambridge in the UK. To see more of David's work please visit his Flickr Photostream. The first inspection of my captured image revealed that the central star was not round. My first reaction was to think that I had some sort of guiding error but I quickly realised that other stars in the image did not exhibit the same feature and this set me to investigate further. Inspection of the central star revealed a blue-white primary star and an orange companion. There is just a hint of the companion visible in the image processed to bring out the nebula and its structure. I reprocessed the data to see what could be revealed by stretching the image only slightly to limit the blooming of star images. I then used this second image as an additional luminance layer on the original image to reveal the companion 14 magnitude orange dwarf star.
This image of the Skull Nebula's (NGC 246) colourful central stars was reprocessed to show the stars and has been enlarged x2 from the original. Image provided by David Davies and taken from Cambridge in the UK. To see more of David's work please visit his Flickr Photostream. Click on the image for the larger version and a closer look at those stars. Image Details
- Telescope: 200mm Ritchey-Chretien.
- Camera: QSI 683 camera.
- Mount: Skywatcher EQ8.
- Software: PixInsight and Photoshop
The data comprise 15 x five-minutes subs each of RGB and 51 x five-minutes luminance subs - eight hours of data.
David Davies - (20 November 2021).
