The Wizard and the Soul
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.
Posted August 2, 2019
NGC 281 Pacman Nebula
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. https://en.wikipedia.org/wiki/Bok_globule
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.
Posted July 29, 2019
Pelican Nebula ( IC 5070 and IC 5067)
Another one from my June 8th narrowband imaging run through the constellation Cygnus. The Pelican Nebula ( IC 5070 and IC 5067) in sulfur 2, hydrogen-alpha, oxygen 3, mapped to RGB.
My narrowband imaging rig: William Optics GT81 (81mm aperture, focal length 392mm, f/4.7), Moonlite Focuser, Pegasus Astro Power, and ZWO monochrome cameras and EFW.
Posted July 25, 2019
Western Veil Nebula in Cygnus
The Western Veil Nebula in Cygnus with the "Witch's Broom" (NGC 6960) toward the top. WilliamOptics GT81 APO Refractor and ZWO ASI1600MM-Pro mono camera: 14 x 300 second exp in Ha, 15 x 300 second exposures in OIII.
Posted July 21, 2019
Nearly Full Moon Rising
Our moon is especially beautiful and bright tonight. Notes: AstroTech 6" Ritchey–Chrétien f/9 1350mm, Nikon D750 32 x 1/500 sec, ISO 3200, stacked in AutoStakkert 3.0.14.
What's cool, is Jupiter is just up along the ecliptic from the moon, and I swung the same setup there and captured a very dim shot of our system's largest planet along with three moons, Europa, Io, and Ganymede.
Another one from earlier this evening, a plane flying through while I was setting the focus on the Nikon/AstroTech.
Posted July 16, 2019
Oversampling for fun and [probably no] profit
Tonight I'm testing out the ZWO ASI071 and the AstroTech RC6, with an Off-Axis Guider (QHY5iii178 guide camera binned 2x2). I've never tried this mix together, so we'll see how it goes. At 1350mm focal length this setup has a 0.73/pixel resolution. So, yeah, it's going to be oversampled. And there's also a big old gibbous moon out tonight, and the weather is not planning to cooperate. My hopes are fairly low.
Posted July 13, 2019
Short nights, narrow bands, works in progress
We probably have less than four hours of seriously dark night this time of year--at my location, coastal New Hampshire. And you have to make do with that. So, last night I spent every minute on hydrogen-alpha frames for three targets, Sh 2-54 (with the star cluster NGC 6604 in the center), NGC 7830 Wizard Nebula, and NGC 281 Pacman Nebula. I went through each of these and shot 30 x 180 second exposures, starting around 10:30 pm, which is still a bit within astronomical twilight.
The nebula Sh2-54 is about 5000 lightyears away in the constellation Serpens. It's part of a long band of nebulosity that extends almost ten degrees through the Eagle Nebula (M16) and Swan/Omega Nebula (M17) below that. NGC 6604 is the cluster of stars above and to the right of the brightest knot of the nebula. Imaging notes: 30 x 180 sec Ha sub stacked in DSS and processed in Photoshop CC.
NGC 7830 is the star cluster surrounded by the Wizard Nebula, an HII region about 7200 lightyears away in the constellation Cepheus. This is 30 stacked 3 minute exposures, no calibration frames.
NGC 281, called the Pacman Nebula for obvious reasons is an HII region in Cassiopeia. Pacman has some amazing features including a batch of really distinct Bok Globules, those small dark nebulae full of cosmic dust that may be playpens for newborn stars. William Optics GT81, ZWO ASI1600MM-Pro, Astronomik Ha 6nm filter, 30 stacked 3 minute exposures, no calibration frames.
NGC 281 Pacman nebula in Ha:
NGC 7380 star cluster surrounded by the "Wizard Nebula" in Ha:
Sh2-54 Nebula and NGC 6604 open star cluster in Ha:
Posted July 9, 2019
DIY Pegasus Astro Pocket Powerbox (almost)
Tonight I'll be testing out the prototype for my DIY version of the Pegasus Astro Pocket Powerbox--well, a manual operation version. There's no ASCOM or INDI support, but with what I've put together here--12vdc line in, 3 x regulated 12v dc 4 amp out, 2 x PWM-controlled dew control RCA jacks (potentiometer with the silver knob controls output temp). Add an Arduino, a few relays, and a temp sensor and I can build all the powerbox features I use. One reason I'm going down this path (I have a pocket powerbox on my GT81 narrowband setup and I love it) is that the Pegasus Astro version doesn't provide 5v dc output, and I want 5v with up to 4 amps out to power the Raspberry Pi 4 + 4GB RAM I'll be building out later this year, running INDI/Ekos/Kstars or Stellarmate. There's also a big price difference. I threw this together for about 15 USD, and I think I paid $180 for the PPB. I'll let you know how it goes!
Here's my test setup for tonight--testing the DIY Pocket Powerbox. This is my ZWO ASI071MC with a Nikon 180mm f/2.8 lens, ZWO ASI120MM-S + 130mm guiding, on my trusty old iOptron CEM25P mount. That's my prototype pocket powerbox on the back, behind the main imaging camera. I'm going to be doing some long exposure color shots in Vulpecula--Sh 2-92, NGC 6820.
