Hi All,
Thought I would sweep around the south celestial pole for some interesting features to image having heard the region contains some dust. What I was not expecting was to come across such a vast complex of dust. This is real Hoover material right here! So it goes without saying, I couldn't resist taking up the challenge of this rarely imaged area;
Nebulae of the Octant
Warning: high resolution versions may take time to load.
Octans is the most southern of southern constellations devised by Nicolas Louis de Lacaille in the eighteenth century. It was named in honour of John Hadley's invention of a double reflecting octant. Astronomers and navigators used this scientific instrument to measure angular distance between the horizon and celestial objects. The constellation hosts the location of the south celestial pole. Unlike the north pole, it has no bright pole star. Sigma Octantis is the closest naked-eye star to the pole alas it is so dim it is difficult to use for navigation. The constellation does not contain many deep sky objects but makes up for it with a complex array of galactic cirrus dust clouds. The dust clouds are faintly illuminated by the energy released from the integrated flux of all stars in the Milky Way and are composed of dust particles, hydrogen, carbon monoxide and other elements.
Dark skies are key for this target. If you're up for a challenge, I recommend giving it a shot. Having produced a mosaic with similar galactic cirrus (
MW9 aka Sarah's Nebula for Mr Sidonio), I somewhat knew what to expect alas I did find it difficult to extract the faint dust which was barely above the background ADU count - very weak signal. This is the first time I experimented with PixInsight in the work flow - DBE and StarAlign with Frame Adaptation. Not sure if I would say this made the work flow any easier. Frame adaptation still has limitations in my view. Manually performing the panel matching still provided a superior result even if it took me three times as long. I've got the time and patience if the result is one of quality. DBE took some getting use to. Completely ripped the guts out of galactic cirrus the first few parses as its signal is so faint, it mistook it as a background gradient. Really need to selectively manage the data points. No doubt I'll look to incorporate further routines into the work flow and experiment accordingly but I don't see it replacing CCDStack and Photoshop any time soon, that's for sure. Shadow/Highlights is just a real gem for this type of work. The data has been pushed rather hard (actually appears sharpened, but its not) to bring out the structure and as such some noise is present in the extremes. Such as life! The signal is faint and tedious to work with. I'm not going to chase it down to get a plastic looking image. Anyway, enough mosaics for a while (I think). A couple of single frame images to come when I get around to them.
Thanks for looking. Hope you enjoy it. All comments welcome.
PS. I've also added an annotated version of the IC4628 image, it can be viewed from the image page.