The Wizard and the Soul

August 2, 2019 - Reading time: 3 minutes

I captured almost 5.5 hours of OIII and SII data on NGC 7380 (Sh2-142) the Wizard Nebula and star cluster in Cepheus, along with a full set of narrowband frames for IC 1848 the Soul Nebula in Cassiopeia.  I timed things well enough that I captured 20 subs each of Ha, OIII, and SII for the Soul before the earth rotated into early morning. Not a ton of data, but enough to process and see how it looks--not bad, in my opinion. My camera rotation is almost 90º off, almost vertical against the long side of the sensor, but I cropped the nebula to a square so you don't have to see how silly that looks. 

I captured the Ha data for the Wizard Nebula early in July, and now I have enough to process in SHO (Hubble Palette) that's where we map the three bandpasses, sulfur (SII), hydrogen (Ha), and oxygen (OIII) to RGB, Red, Green, Blue to make up a color image. 

Here's NGC 7380, Sharpless 2-142, Wizard Nebula:

IC 1848, the Soul Nebula:

I don't know if I succeeded but I was trying to get more hydrogen green back into the arrangement. Most of the nebula is hydrogen--just going off the signal in the Ha frames compared with the OIII and SII data. The rims of both regions of IC 1848 are thick with sulfur--red and green gets us that golden brown, but I think the processes, filters, actions typical for astro imaging go too far in reducing green in the images, bending it more toward blue. This does have the benefit of bringing out oxygen, which is nowhere near as plentiful as the blues I see in most SHO/Hubble Palette images. That's just what everyone's come to expect from a "Hubble" image. On the other hand this is one of the coolest aspects of the hobby, the ability to go back and re-processes your data, because you have new or improved processing tools or skills, a new set of data, or simply because you want to experiment with color allocation.

I woke up around 3:30 am and went out to check on the night's imaging run. I was in the middle of the sulfur2 frames when I took this shot with the Nikon: the William Optics GT81 APO refractor pointed at Cassiopeia (top left), actually just below it, which is where you will find IC 1848, the Soul Nebula. Just so you are aware, this is all automated--slewing, plate solving, focusing, filter rotation, and image capture. Once I plot and schedule an imaging run, the last place I want to be is near the telescope where the slightest motion in the ground can ruin a good 5-minute exposure. I was just out there to look at the beautiful sky, and take some crappy blurry photos of my astro gear against the starry background.

NGC 281 Pacman Nebula

July 29, 2019 - Reading time: ~1 minute

NGC 281 Pacman Nebula - I'm finally getting around to processing a bunch of data I gathered over the last month and a half. Pacman is one my favorite nebulae in Cassiopeia. I love that it's out on its own, surrounded by cold dark space and a field of stars. NGC 281 also has an impressive set of Bok Globules, those dark gaseous knots drifting in front of the bright blue and gold (oxygen and hydrogen). And that's Achird (eta Cassiopeia) at the bottom left, a variable double star a little under 20 lightyears away. Damn, that's nearly close enough to visit--with the right technology.

Another one of the Pacman Nebula NGC 281, with narrowband data I started taking in early June. You can really see the Bok globules, those little lumps of dark dust and gas standing out near the center and backlit by the bright emission of the Pacman.

Imaging notes: William Optics GT81 at f/4.7 with WO 0.8x Flat6A II, Astronomik Ha, OIII, and SII filters, Moonlite focuser, ZWO ASI120MM OAG, Imaging camera: ZWO ASI1600MM Pro cooled mono on an iOptron CEM25P mount. Stacked in DSS, processed in PS CC 2019.