Back with the GT81 and color targets shot in HaGB
Messier 13 (NGC 6205) Globular Cluster in the constellation Hercules. I shot this in hydrogen-alpha (Ha) + Green and Blue, mapped to RGB color, with 40 x 30-second exposures for each. Notes: William Optics GT81 apo refractor + Flat 6AII, ZWO ASI1600MM-Pro mono camera with Astronomik 6nm Ha, Baader broadband GB filters, Moonlite focuser, iOptron CEM25P mount.
This one's a little more subtle. The bright, irregular HII region on the left is Sh 2-90 in the constellation Vulpecula, along with concentric swirls and knots of interstellar dust that make up the dark nebulae LDN 800, 806, 807, 808 (right side). 70 x 180-second subs Ha, 42 x 180-sec subs Blue, 39 x 180-second subs Green. I lost a batch of my broadband frames to some fast moving clouds, but managed to process what was left into a reasonably decent shot.
Setup for the night: iOptron CEM25P mount, William Optics GT81 Apo refractor with FLAT 6AII (382mm fl, f/4.7), Moonlite focuser, Orion Thin Off-Axis Guider with QHY 5iii178 guide cam, ZWO EFW with Astronomik 6nm narrowband filters (Ha, OIII, SII), Baader broadband Green and Blue filters), ZWO ASI1600MM-Pro cooled monochrome camera, Pegasus Astro Pocket Powerbox for dew control, temperature, humidity reporting. Controller: Fanless i5 Windows 10, ASCOM, Sequence Generator Pro.
Posted June 1, 2020
Saltwater Witch Micro-Observatory Project
Here’s my situation--and I think this a common one: there is a limited amount of clear night sky--and that’s with or without the moon. I have a limited amount of time to set up all the gear necessary for a night’s imaging run. I don’t have an observatory in my backyard with everything ready to go, mount polar aligned, cameras cooling down, roof or dome rolling back.
But what if I had something like a self-contained, weather-proof box with just enough room to fit an equatorial mount and a scope? Even if it’s not my main mount and scope, wouldn’t it be nice to have an astro setup ready to go at any time--ready for the next break in the clouds?
That’s where I started with this micro observatory project. My goal is to be able to set up a self-powered astrophotography system that can remain in place through any weather while protecting the equipment, and be operational and ready to image within a few minutes. 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.
This is what I’m shooting for:
- Weather looks clear enough to imaging.
- Select a target or two for the night.
- Walk out to the micro observatory and unlatch the lid, set it aside, take off the telescope cap, power up everything, move mount from parked position (horizontal) to a home position, weights down and pointed at the NCP. Walk back the house.
- Remote into the astro controller (i5 Windows 10 machine) and load an existing sequence or create a new one for the selected targets.
- Ready to run!
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 giant water-tight SKB plastic molded shipping container with 27”/68.5cm interior dimensions--it’s a cube. It's made from really sturdy impact resistant and UV stabilized polyethylene (LLDPE), with stainless steel latching hardware. The stock hinges and straps didn’t work for my purpose--I’ve drilled off the hinges.
Here’s the SKB shipping case I’m using:
SKB R Series 2727-27 Waterproof Utility Case
https://www.skbcases.com/industrial/products/prod-detail.php?d=s18&id=333
I running some temperature and humidity tests right now--it’s very humid and around 86F/30C --so pretty warm. I also had this box out in the yard, closed up and latched all winter long, and temperatures regularly get down (and sometimes stay down) to well below zero F, around -20C.
So far so good on the temperature--as long as I cover with a reflective cover. My box temp sensor in the box has the humidity well below outside ambient, and the temps are maxing out around 82F/27-28C. That’s warm but destructive, and I wouldn’t be operating the mount at those temps.
Roll the video...
Posted May 29, 2020
First imaging run with N.I.N.A.
Last night I was out with the William Optics SpaceCat, CEM25P mount, and the ZWO ASI071MC color camera to run some analysis on guiding, which hasn't been excellent lately--trying to determine the cause, but also to try out some new astronomy control software: N.I.N.A., which stands for Nighttime Imaging 'N' Astronomy. It's free, open source software that has interested me for several months. Find it here: https://nighttime-imaging.eu/ I first downloaded it last October and did some daytime testing, connecting cameras and a mount, but I haven't been back to it until yesterday. I like and regularly use both Sequence Generator Pro with ASCOM on Windows, and Ekos/KStars with INDI on linux. Both work equally well, with advantages and disadvantages, with features I like and don't. The framing and mosaic wizard in SGP is unbeatable. I like the guiding process built into Ekos way more than PHD2, along with the extreme portability and performance you get with INDI/KStars/Ekos on a Raspberry Pi 4 SMB. They are fantastic apps, worth checking out to see what works for you and your setup. Some may point out that SGP has a price tag, but at only $99 US, I would still put it in the same "basically free" category as Ekos.
NINA certainly has my attention after last night's imaging run (I installed version 1.10 BETA007, which ran beautifully). I have been using SGP and Ekos for years, and for the most part they are solid working applications that have delivered quality imaging, automation, and equipment control. Of course--like everyone, I have also experienced dozens of wasted clear nights because software didn't function correctly, drivers failed, intermittent hardware issues, voltage and current issues. Maybe that's just part of engaging in a technical hobby like astronomy and astrophotography. You learn to troubleshoot weird problems in the dark, half-asleep and staggering out to your gear in the early morning hours. But it's when you see a nebula or galaxy appear in the SGP or Ekos or NINA image window after a five-minute exposure, that makes it fun, and maybe solving those problems seems worth it. Usually.
NINA, like SGP, is a Windows app and sits on top of ASCOM protocols and hardware specific integrations, so if SGP works with your cameras, mount, focusers, filter wheels, etc., chances are NINA will also work.
And NINA really shines with its modern design, intuitive system workflow, and noticeably quick processing speeds when imaging, focusing, and plate solving. There's some brilliant application design built into NINA at the foundation, in the way it allows a new user to experiment, to just try something, click the autofocus button without the sense that you won't be able to find your way back if it goes sideways. Many Windows apps are designed with a very structured user path that guides you toward completing a milestone or reaching a given endpoint with no way to stop and go back before you get there. On the other hand, NINA seems to have been designed with almost continuous access to all the equipment tabs, configuration options, immediate saves for configuration changes, even when other processes are running.
NINA is also a complex app that provides a complete astro imaging, planning, and automation workflow, and I found myself jumping around to different tabs and panels, looking for things throughout the night. I quickly found just about everything I was looking for. At some point last night I was thinking I should be able to make tweaks to a sequence while it's running--like you do with SGP, but that wasn't a serious issue since it only took a moment to stop, edit, and restart the sequence. I struggled a bit with autofocus, but I didn't spend any time configuring or calibrating it--and that would be the same with any astro app.
Here are a couple stacked test shots from last night, reasonably processed in PSCC2020. Top centered is NGC 6604 open star cluster in Serpens, and Sh2-54 (GUM 84) is that bright block of ionized hydrogen just above center. That's Messier 16, Eagle Nebula going out of frame at the bottom. The second image is NGC 7000 North America Nebula, with the Pelican to the right of it across that gulf of dark dust and nebulosity. That's the blue supergiant, Deneb in the upper right corner, the brightest star in Cygnus, and 19th brightest in the night sky from our point of view. 20 x 240 second subs, no calibration for each target. For M13 I shot 200 x 30 second subs, and no cal frames.
Another couple from last night--first is my setup for the night, and in this shot I'm actually in the middle of a 200-sub exposure sequence of M13, image below.
Screenshot of the N.I.N.A. UI during the M13 imaging run:
Posted May 24, 2020
NGC 6820 in HaOIII
Another one from the one clear night we've had for a while--Wednesday the 13th. This is centered on the reflection nebula NGC 6820 (that bright nebula core) and the open star cluster NGC 6823 in the constellation Vulpecula. All of this is wrapped in the emission nebula, Sh 2-86, basically everything else in the frame, all the cloudy structures that surround NGC 6820 and 23. Reading the wikipedia page, it says NGC 6823, the star cluster in the center, "forms the core of the Vulpecula OB1 stellar association". It's true: https://en.wikipedia.org/wiki/Vulpecula_OB1 --that sounds very Star Federation, which is cool. Astro Notes: William Optics SpaceCat 51 250mm fl Apo Refractor, ZWO ASI1600MM-Pro cooled monochrome camera, iOptron CEM25P EQ mount, Astronomik 6nm Ha and OIII filters. 20 x 480 second exposures for each filter.
Posted May 15, 2020
The Pinwheel Galaxy in HaGB (no red filter)
The Pinwheel Galaxy (M101) could be our galaxy's giant cousin--very distant cousin, since it's 21 million lightyears away (that's like 6 megaparsecss to you serious astro nerds). It's almost twice the diameter of the Milky Way galaxy, with a trillion stars. But what also makes the Pinwheel so wonderful is the way it's angled, so that we see it from the top (or face?).
I shot this in three sets of images, first with hydrogen-alpha, then with broadband green and blue filters, so instead of a normal red filter, I'm using narrowband Ha, which only allows a fraction of the hydrogen bandpass through--on the red end of the spectrum. I know HaRGB is popular, using the stacked Ha frames for a luminosity layer, but I only have five slots in the filter wheel, and thought I'd give this a try. (My filter order: Ha, OIII, SII, Green, Blue).
Here's M101 in HaGB mapped to RGB color, so that the galaxy's massive H II regions (pink and red masses swirling along the Pinwheel's spiral arms) really stand out. If I shot this in normal broadband red, these would just blend into the overall color of the galaxy. Astro Notes: William Optics SpaceCat 51 250mm fl Apo Refractor, ZWO ASI1600MM-Pro cooled monochrome camera, iOptron CEM25P EQ mount, Astronomik 6nm Ha filter, Baader Green and Blue filters.
I shot the 60 sub-exposures that make up this image (20 subs for each filter) with everything you see here:
Posted May 14, 2020
SpaceCat 51 Autofocus
Another autofocuser configuration I'm trying out with the William Optics SpaceCat51 and the Deep Sky Dad AF3 stepper and focus ring. The goal is portability, and I have the motor and controller bolted to a guide-scope shoe that can be easily added or removed from the scope. I 3D printed a tension adjustment bracket--that's the gray half-cylinder piece on the opposite side of the handle.
Posted May 9, 2020
Andromeda from the Galactic Edge
Here's the Andromeda Galaxy (M31) without the stars and other clutter from our own galaxy in the way. I have processing tools that will algorithmically remove stars from an image, and it does a reasonable job. What I'm showing here is what Andromeda would look like if you could travel from our location on the Orion Spur (a minor branch off one of the Milky Way's spiral arms), pass through the Perseus Arm, to the edge of our galaxy, and then take some pics of M31. Our star, the Sun, sits in the middle of one side of our galaxy. We are so used to seeing a star field in astro images we do not realize all the stars we can see in the night sky--with our eyes, are in our own galaxy. Some of those pinpoints of light are galaxies themselves but are so far away they appear no different from stars to our eyes. In this image of M31 the two star-like objects above and below Andromeda are M110 (larger, below) and M32 (above). These two are actually satellite galaxies that orbit Andromeda. Yes, just as stars have planets, and planets have moons, large galaxies can capture other galaxies in their gravitational pull. Our galaxy, the Milky Way, has several in orbit, including the Large and Small Magellanic Clouds.
Posted April 28, 2020
Updated William Optics SpaceCat 51 setup with Autofocus
If you have seen some of my videos and blog posts on the Cat you know I have two astro camera trains, one color, one narrowband. This one consists of a ZWO ASI1600MM-Pro mono, ZWO ASI filter wheel with Astronomik 6nm HA, OIII, and SII filters, along with a CLEAR in slot one, and a near-IR filter in the fifth position.
Another reason I want to show off this setup is the single-power wire config. Everything else is on the scope or controlled wirelessly--for example, the iOptron CEM25P or my Orion Atlas can be controlled by Ekos through wifi or bluetooth.
I shot some beautiful color images earlier this year and late last. I'll show M31 and a couple others later, but with that color setup I was running multiple power cables and a heavy duty USB cable to the scope, and although this is setup, which I will try out as soon as it clears up, looks a bit cluttered, I want fewer cables running from cameras, controllers, focusers, and other devices. Fewer cables reduces the chance of one of them hanging up on the mount, or swinging just enough with a gust of wind to throw guiding off.
The controller--the aluminum box on the left side is a Raspberry Pi 4 with 4 gigs, running INDI, Ekos, KStars. I remote into this just like I would with with Windows to run Sequence Generator Pro. The only difference is this box is mounted to the scope. I am looking at running my Windows-based astro controller and sequencer stuff on a similarly small single board computer, and then I can just swap out one system for another. 4 USB ports on the Pi, though, really does make things easier.
I am using the DeepSkyDad AF3 belt-drive autofocus, with the helical focuser timing belt ring made for the cat. I think Pavle at DeepSkyDad sells the components by themselves if you're interested in doing something like this. The rest of it is made up of various SmallRig camera rails, clamps, and support pieces.
I also have GPS via a USB dongle to automatically get accurate date, time, longitude, latitude, and altitude for Ekos and KStars.
Of course, as is typical, I'm ready to go and the weather's supposed to cloud over in the next couple hours, right around sundown. Hmmm. It's almost as if there's a conspiracy.
I don't normally need dew control this time of year and maybe halfway through the summer, but I will add a dew heater when I need to, but still keeping with a single 10 - 15 amp 12 volt dc line in, and I'll see if that's enough to drive all the devices. Planning this stuff out is half the fun.
That white rectangular shape under the Raspberry Pi is a DC step down converter, taking 12v dc to 5v at 5 amps. The Raspberry Pi 4s need a bit more current then the older 3s.
Before I pack it up, I want to show off a couple astro images from a couple different imaging runs.
The first is the Rosette Nebula NGC 2237 in Monoceros, a large circular HII region. The open star cluster NGC 2244 has formed out of—and continue to form out of—the Rosette's abundance of hydrogen and other materials. NGC 2237 is about 5000 lightyears away from us, and it's about 130 lightyears across. That's Sh2-280 on the right, a dim diffuse nebula. Another one from my backyard with the William Optics SpaceCat 51 250mm FL APO refractor, iOptron CEM25P EQ mount, ZWO Astronomy Cameras ASI071MC cooled color camera, Celestron UHC/LPR filter. 13 x 2-minute exposures, 4 x 8 minute exposures.
One more from my backyard with the WilliamOptics SpaceCat 51 refractor and the ZWO ASI071MC camera: the grandest of the galaxies, Andromeda, M31. Of course, there are millions of incredibly beautiful and strange—and even downright bizarrely structured galaxies out there in the universe, many within normal telescope distance, but in my opinion they don't come close to M31. You could argue the Pinwheel Galaxy (M101) is in the running because it is so perfectly positioned from our perspective, a wonderful top-down view of a spiral galaxy. But Andromeda is like the Platonic ideal of a spiral galaxy. M31 also happens to be our largest galactic neighbor. So at 2.5 million lightyears away, it's close by. It's also much larger than M101, with a trillion stars and a hundred thousand lightyear diameter. This is probably one of the first objects an astronomer or astro-imager in the northern hemisphere is going to view or capture. You can see it without a telescope on a clear dark night. Andromeda Galaxy was first documented by astronomer 'Abd al-Rahman al-Sufi in 964. He described it as a "nebulous smear" in his famous Book of Fixed Stars, which is exactly what it looks like without a telescope—and if you know where to look. It's in the constellation Andromeda, so that should get you pointed in the right direction if you're inclined. Note: This image is a combination of RGB color and near-infrared frames I captured earlier this year and late last year. I'm just getting around to processing them!
Okay, so that's it for now. Just a quick walkthrough of my narrowband rig with the William Optics Space 51 and autofocus. And with a single cable running to the setup. So, this setup really is plug in the power, polar align, and start taking subs.
Well, we'll see how easy it is once we get some clear night sky!
