After weeks of waiting for decent weather, I finally managed to complete my first picture with the dual-band filter Antlia ALP-T.
First impression: it is an excellent filter, no reflections, transmission rate as expected, and producing a very clean image. Not a cheap one, but definitively worth the price.
The image total exposure was pretty short, limited by the low trajectory on the horizon and the season, but long enough to capture some of the nebula's external halo.
NGC2359NGC 2359 is also known as Sh2-298 or RCW 5 or Gum4, and is a wind blown bubble ionized by the Wolf-Rayet star WR 7 (HD 56925) shown in the annotated version.
It is commonly nicknamed Thor's Helmet, but in the orientation presented here frankly I see more a squirrel head (looking right) - a more peaceful view.
The nebula is approximately 3670 pc away and 30 ly in size. WR7 is an extremely hot star thought to be in a pre-supernova stage of evolution. It is similar in nature to the
Bubble Nebula, but interactions with a nearby large molecular cloud are thought to have contributed to the more complex shape and curved bow-shock structure of Thor's Helmet.
Picture: Artist's (!) Impression of the squirrel hidden in the Thor's Helmet
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