Messing around with Messier in Infrared

May 23, 2019 - Reading time: 5 minutes

We finally had several hours of clear night sky--not spectacular, but I'll take what I can get this time of year. That whole “April showers bring May flowers” thing really applies to this region of the planet. I think we’ve had four or five full clear nights in the last couple months--and I can’t remember multiple clear days in a row, but I am looking forward to more opportunities to capture the night skies soon--early summer through the winter.

One of the paths I’m currently on is to be more productive--in very concrete terms. I simply want to produce more imaging data per night than I have before. One way to do this is to upgrade equipment and pile on new devices, which translates into an EQ mount with more capacity and another scope and camera to double the exposure time. In other words, spend more money, which I don’t want to do.

Another option is to improve the efficiency of my current setup and systems. This is where I’m presently spending my time and effort, squeezing out 5-10 minutes per hour I was losing with slower hardware and application workflows (per image download times, auto-focus and plate-solving routines, etc). I will test out NINA (https://nighttime-imaging.eu) at some point, because I’ve heard great things about its speed. I’m currently using Sequence Generator Pro 3 with my narrowband refractor setup (William Optics GT81, Moonlite Focuser, ZWO ASI1600MM-Pro mono, and ASI120MM-Mini Guide-cam), and with a few exceptions and idiosyncrasies, which often turn out to be ASCOM or device-specific weirdness, not an SGP problem, things are going smoothly.

I have been working through a couple different configurations of equipment, automation systems, and application workflows, mostly focused on building a narrowband setup with two cables--USB3 and a single 12vdc 10 amp line.  For now, I’m using Windows 10 on a fanless Celeron-based system, which easily handles the processing load during capture and plate-solving. On the scope itself I have the Moonlite Focuser controller, a powered USB 3 hub, and all power, environment, and dew control functions managed through a Pegasus Astro Pocket Powerbox.  

I ran my first in-depth test of this system last night, jumping all over the sky east of the meridian, taking several 1-minute subs of M3, M10, M12, M13, M51, and NGC 6826 (blinking planetary nebula in Cygnus). I have to say, my impression of SGP has not changed. I already had a high opinion of it, and coming back to it for version 3 has been fun and exciting--and more importantly, productive. I was skipping all over the sky last night, pulling up the Framing and Mosaic wizard half a dozen times, and appending new targets to the sequence. I would have kept going after midnight, but the clouds rolled in and shut the show down.

Near-IR filter notes--something to consider if you’re guiding off-axis: I’m using Astronomik 1.25” narrowband filters (Ha, OIII, SII) in this ZWO EFW, but I also have an Optolong IR 685nm longpass filter installed in the 5th place. I ran into a slight issue with off-axis guiding because the IR filter’s focal offset with the Astronomik’s is so great that it throws off the focus of guide camera. I have to plan to do any near-IR exposures at the end of any sequence because this forces me to adjust the focus in PHD2 for the ZWO ASI120MM.

Here are a few shots from last night, using the Optolong 685nm longpass filter.

Whirlpool Galaxy (M51) in near-Infrared, WIlliam Optics GT81, ZWO ASI1600MM-Pro mono, 685nm Near-IR longpass filter. M51 is around 23 million lightyears away from us in the constellation Canes Venatici.  It’s a tiny view of the galaxies, but I’m impressed with the trailing gas and dust that IR managed to capture.

M10 (NGC 6254) is a globular cluster of stars about 14,000 lightyears away in the constellation of Ophiuchus. 4 x 60 second subs in near-Infrared, William Optics GT81, ZWO ASI1600MM-Pro mono, 685nm Near-IR longpass filter. In IR the stars are really distinct in the cluster, and I want to come back with RGB and use the IR frames for luminance, and see how that looks.

Messier 3 Cluster:

Messier 13 Cluster in Hercules:

Messier 13, Hercules Globular Cluster (also NGC 6205) - using the IR image as luminance with an old RGB version of M13:

Messier 12 Cluster:


Astro Session: July 9, 2018

July 9, 2018 - Reading time: 3 minutes

I recently bought the William Optics FLAT 6A II, and finally made it out under the stars to take some sub-exposures. I paired it with my GT-81 and ZWO ASI071MC color CMOS camera. The FLAT 6A II is a 0.8x reducer/field flattener; it's adjustable for different focal lengths, and so far, with my limited use, it appears to be quite a leap over the old William Optics F6-A I've used for a few years. The ASI071 has an APS-C sized sensor, and anyone with a large sensor astro camera or DSLR knows if you don't want field curvature with your refractor you need some sort of flattener. The FLAT6AII design makes it easy to dial in the correct distance for the scope you're using. The old reducer/flattener worked, but I had to test out a dozen different flattener to sensor distances, and still had to do some cropping and processing to fix the corners. This new FLAT 6AII provides a fairly flat field across the entire view. Equipment: William Optics GT-81 + FLAT 6A II 0.8x reducer f/4.7, ZWO ASI071MC-Cool color CMOS camera - gain 0 offset 8, ZWO ASI120MM-S Guide Cam + 130mm guide scope.

Testing:

With the GT81 and ASI071 I get a 3.54° x 2.35° field of view, and I can capture some big chunks of the night sky. Here are three from the last two nights: [1] the Pelican Nebula (IC 5070) and the edge of the North America Nebula (NGC7000) at the bottom, [2] IC 1396 nebula with the Elephant's Trunk at the top and the Garnet Star bottom left, and [3] M31, our galactic neighbor, the Andromeda Galaxy. 

 

 

Pelican Nebula image info: ZWOASI071MC 39 x 240 second color subs stacked in DSS, processed in PSCC2018

IC 1396 region image info: ZWOASI071MC 21 x 300 second color subs stacked in DSS, processed in PSCC2018

The Andromeda Galaxy. The last time I photographed Andromeda (M31) was 2015, maybe fall of 2014? It's been a while. I was using a DSLR--that was the only camera I had, and I had it on a terribly-used Celestron CG-5 equatorial mount with some aftermarket RA/DEC motors. By "terribly-used" I mean you could drive a truck through the gear backlash. Even so, I still managed to get some decent 30-second exposures of Andromeda, Orion Nebula, and other big bright targets in the sky. Well, I'm back with our galactic neighbor, and with much better gear: 192 x 120-second sub-exposures stacked in DSS, processed in PSCC2018, ZWO ASI071MC camera at -10C, William Optics GT81 APO, iOptron CEM25P EQ mount.


Astro Session: July 7, 2018

July 7, 2018 - Reading time: 3 minutes

Our galactic neighborhood, looking toward the center, with 13 stacked 15 second exposures, Nikon D750, Rokinon 10mm f/2.8 lens. What's crazy is this is with a decent DSLR camera, lens, a tripod, and some free image stacking software (DSS). I did the stretching in Photoshop CC--"stretching" is when you adjust contrast, intensity values, to bring out the features of whatever you're shooting--in this case the north end of the Milky Way Galaxy, our home. Let me point out some interesting features: starting at the left, that vivid red star is the "Garnet Star" (Mu Cephei), and that's right next to some cool nebulosity that includes the Elephant's Trunk Nebula (IC 1396), a little ways along, you see that blocky reddish region? That's the North America Nebula (NGC 7000) with the star Deneb (19th brightest star in the night sky). Deneb forms the northernmost (leftmost in this shot) point of the famous "Summer Triangle". The other two points are Vega, the 5th brightest star in the night sky (to the right and above the Milky Way core in this shot), and Altair (12th brightest) a little more to the right and below the Milky Way core. Moving along the galaxy to that bright region on the bottom side of the core, about halfway between Altair and the powerlines--if you really zoom in, you'll see the Wild Duck Cluster (M11). Now look just left of where the powerlines cross, those grayish-pink cloudy areas? That's where you will find the Eagle Nebula (Messier 16, NGC 6611) and the Swan Nebula (M17). That bright point of light in the middle of the powerlines is the planet Saturn, which is moving along the ecliptic and right now it's in a pretty good place for viewing. Just right of that are a few more cloudy areas. That's where you would look for the Lagoon Nebula (M8, NGC 6523) and Trifid Nebula (M20, NGC 6514). Somewhere along the Milky Way--this is where you will mostly likely find me focusing my telescope all the through the summer and fall. I almost see this shot as a map of places to visit from afar, and the cool thing is you really don't need to setup the astro gear for this. You can create your own galaxy map, as long as your camera can handle long exposures (not that long, only 15 seconds) and you have it on a tripod with a remote shutter control. And this is only part of the sky from where I'm standing on our little planet! Another way to put this image in perspective is here in the northern hemisphere, around 43° latitude, I don't have enough of a view south (blocked by hills and trees) to see Sagittarius A*, which marks the center of our galaxy, and this far north there's a sky full of other galaxies, a large section of our own galaxy, nebulae, and other deep space objects that I can't ever see from here--that I would have to travel below the equator to see. Some day! 


Astro Session - November 10, 2017

November 10, 2017 - Reading time: ~1 minute

M33 Triangulum Galaxy, about 3 million lightyears away, so... not that far. M33 is a relatively small spiral galaxy with only 40 billion stars. I'm having some trouble with my guide camera (ZWO ASI120MM), so this is all unguided. I took 80 LRGB exposures--120 seconds each, 10 Ha frames at 120 secs, 20 dark calibration frames, stacked in DSS). 


Astro Session - October 17, 2017

October 17, 2017 - Reading time: ~1 minute

Color version of M81 (Bode's Galaxy) in the constellation Ursa Major (Big Dipper). From another set of subs I shot at 4am--this time with the color QHY CMOS camera, QHY5III178. Info: 21 x 300 sec. with 20 dark frames, QHY5III178 color CMOS, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control. 


Astro Session - October 12, 2017

October 12, 2017 - Reading time: ~1 minute

M81 (Bode's Galaxy) and M82 (Cigar Galaxy) in the constellation Ursa Major (Big Dipper). I was up at 4am, and there's the big dipper swinging around and climbing into the sky. Bode's and the cigar galaxy were just waiting to be captured. Info: 15 x 120 sec. with 10 dark frames, Atik414Ex mono CCD, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control.