November 24, 2018 - Reading time: ~1 minute

If you're looking for my old Astro Journal with my Equipment and Astro Automation pages: https://SaltwaterWitch.com/astronomy


Micro-Observatory Project #1

August 18, 2019 - Reading time: 3 minutes

My goal with my “micro-observatory” project is to be able to set up a self-powered astrophotography system that can remain in place through any weather while protecting the equipment, be operational and ready to image within a couple minutes, and be moveable--if necessary. I don’t need it to be fully automated for now. This is a fairly complicated setup, and so I’m going to take this in steps. The main missing piece of automation is raising and lowering the lid. Of course, all the astro gear is automated, except for a motorized cap, which won’t be necessary without the ability to remotely open and close the lid.

I started testing this idea a couple years ago with wood frames, and even did some research on wood shipping crates. I settled on this plastic molded shipping container with 27”/68.5cm interior dimensions--it’s a cube. So far, this looks like it might work. The stock hardware is crap--I already drilled off the hinges, and I’m looking at 180 degree hinge mechanisms and other options for lifting the lid away with minimal obstruction of the sky (https://youtu.be/6bMMZq0X29E). Whatever I end up with will have to be pretty sturdy because I’ll be mounting a 50 watt solar panel on the lid to keep the batteries charged. 

As far as project progress, I’m still at the beginning. I’m testing out different mount/scope configurations for fit--with the scope and counterweights horizontal. I was surprised to find the Orion Atlas EQ-G fit with a small refractor--just barely, and only with west-side travel and no meridian flips. (I had to move the mount and aluminum mounting frame all the way to one side to make this configuration fit). Today I’m trying out the iOptron CEM25P, with the hope that this will fit entirely in the box, centered, and be able to do flips and reach most of the sky.

I’m going to spend a while doing weather and motion testing, anchoring to the ground and monitoring temperature and humidity. It’s water-tight, so I’m not worried about leaks. I just don’t want internal temps or condensation to build up this time of year, or in the winter, to drop below the equipment specs. I haven’t decided what I’ll do for warmth when it’s cold outside. It’s not unusual for the temperature to remain well below freezing for extended periods of time (-6F / -20C is not unusual).

Much to do. I’ll keep you posted!


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. 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.


Pelican Nebula ( IC 5070 and IC 5067)

July 25, 2019 - Reading time: ~1 minute

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. 


Western Veil Nebula in Cygnus

July 21, 2019 - Reading time: ~1 minute

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.


Nearly Full Moon Rising

July 16, 2019 - Reading time: ~1 minute

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.


Oversampling for fun and [probably no] profit

July 13, 2019 - Reading time: ~1 minute

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.


Short nights, narrow bands, works in progress

July 9, 2019 - Reading time: 2 minutes

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: