Imaging Star Clusters with the AT6RC and the ZWO ASI071MC-Pro

M13 globular cluster imaged with the AT6RC, 6” Ritchey Chretien telescope.

M13 globular cluster imaged with the AT6RC, 6” Ritchey Chretien telescope.

I spent a few nights this week trying out my color camera, the ZWO ASI071MC-Pro on the AT6RC. I really love the pixel scale achieved here with the combination. It provides very nice resolution and a moderate field of view. I managed to divide my time between the two clusters. Four hours or so on M53 and about two hours on M13. I honestly wish I had a few more hours on M13, as there are a lot more stars to bring out that are quite dim around the edge of the cluster.

Both images were stacked, integrated, calibrated, light pollution removed, and color corrected with Astro Pixel Processor. I then took them into PixInsight for denoise, stretching, and color saturation.

M53 globular cluster.

M53 globular cluster.

AstroPixel Processor 1.072 Released


The latest version of Astro Pixel Processor has been released.

Lots of support for Sony cameras has been added.

Improved Drizzle/Bayer Drizzle.

Lots of changes and improvements to

  • Image EXIF data,

  • console panel

  • progress monitors

  • Improved loading for frames

  • fixed some memory issues

  • dynamic distortion correction.

  • Improved star analysis

  • GUI frame panel scrolling

Head over to the APP website to get the latest version. Take a look at the full update notes here.

KStars/EKOS 3.1 is released!


An update to my current favorite imaging platform has been released. In this release there’s a bunch of 3.0 fixes as well as a hand full of new features.

  • Fixes to the scheduler to cover some multi-object multi-night scheduling.

  • Ring-field focusing, an improvement to star selection methods for focusing.

  • Updates to the meridian flip code.

  • Huge updates to the official documentation.

  • Polar alignment routines for non-GOTO mounts.

  • Live view for DSLR’s so you can now focus easier.

  • A host of other random fixes and improvements.

Get the updated file at the Kstars download site.

Quick note for Mac users: there’s a bug with offline plate solving in this release, and is expected to be fixed soon.

Revisiting IC 417 on the ES 102mm


I decided to revisit IC 417 but this time with a wider field of view. The image was previously taken with my AT6RC, and it focused primarily on IC 417. But this time I was able to frame it such that I also got the open cluster NGC 1907, as well as the smaller nebula below IC 417, NGC 1931. I’m really happy with how it turned out.

Imaging details

Imaging telescope or lens:Explore Scientific ED102 FCD-100 CF

Imaging camera:ZWO ASI1600MM-Cool

Mount:Celestron CGX

Guiding telescope or lens:Stellarvue F050G

Guiding camera:ZWO ASI290MM Mini

Focal reducer:Stellarvue SFFR102-2

Software:Kstars/Ekos,  Astro Pixel Processor,  PixInsight 1.8 Ripley

Accessories:Moonlite High res stepper motor and Mini-V2 controller,  MoonLite CF 2" Focuser

Resolution: 4432x3235

Dates:Jan. 4, 2019,  Jan. 5, 2019

Astrodon Tru-Balance H-a 5nm: 125x180" (gain: 200.00) -15C bin 1x1
Astrodon Tru-Balance OIII 5nm: 112x180" (gain: 200.00) -15C bin 1x1
Astrodon Tru-Balance SII 5nm: 80x180" (gain: 200.00) -15C bin 1x1

Integration: 15.8 hours

Darks: ~50

Flats: ~50

Bias: ~50

Avg. Moon age: 28.56 days

Avg. Moon phase: 1.31%

Bortle Dark-Sky Scale: 6.00 job: 2454319

RA center: 82.351 degrees

DEC center: 34.736 degrees

Pixel scale: 1.380 arcsec/pixel

Orientation: 92.987 degrees

Field radius: 1.051 degrees

Locations: Home Observatory, Pearland, Texas, United States

Data source: Backyard

Narrowband Imaging IC410 and IC417

IC410 imaged on the Explore Scientific 102mm FCD100 APO refractor.

IC410 imaged on the Explore Scientific 102mm FCD100 APO refractor.

Over the last two weeks, I’ve had 3 imaging nights. KStars & EKOS 3.0 were released which fixed a ton of long standing issues with the scheduler. In addition to that nice software update, I got a Celestron CGX for Christmas! So, those two things combined and I set my sights on the only northern region available to me from the back yard and imaged IC417 on my AT6RC, and IC410 on my Explore Scientific 102mm FCD100 scope.

Here’s a recent photo of the setup.


So far it’s worked great. Average RMS has been between .6 and .8. My AVX was hovering between .8 and 2.0 RMS. I think I can get the CGX tuned a little more in guiding to get those numbers even lower, but have not attempted any adjustments. These are the numbers I’ve been getting without changing any of the default guide settings.

IC 417 imaged on the AT6RC from Astro-tech.

IC 417 imaged on the AT6RC from Astro-tech.

KStars/EKOS 3.0 released with new features


The team behind KStars and EKOS have been busy wrapping up a new version of their imaging software just in time for the holidays. There’s a lot of new features in this one.

The first major feature is the XPlanet solar system viewer developed by Robert Lancaster. It’s a significant upgrade over the built-in viewer.

Robert also created a new interface for the FITS viewer which can how show you all the data of your images in a new side panel which features the FITS header info, Histogram, Statics, and recent images.


Additionally, Eric Dejouhanet dedicated time to a huge scheduler rewrite. The scheduler system previously allowed for scenarios where you could have conflicts in operations, but with the rewrite all this has been fixed and numerous improvements have been added:

  • Dark sky, which schedules a job to the next astronomical dusk/dawn interval.

  • Minimal altitude, which schedules a job up to 24 hours away to the next date and time its target is high enough in the sky.

  • Moon separation, combined with altitude constraint, which allows a job to schedule if its target is far enough from the Moon.

  • Fixed startup date and time, which schedules a job at a specific date and time.

  • Culmination offset, which schedules a job to start up to 24 hours away to the next date and time its target is at culmination, adjusted by an offset.

  • Amount of repetitions, eventually infinite, which allows a job imaging procedure to repeat multiple times or indefinitely.

  • Fixed completion date and time, which terminates a job at a specific date and time.


A few other enhancements are a new scripting and DBus system allow for 3rd party applications to take advantage/control of features with EKOS which will open up the system for more options down the road.

Other improvements and new features can be found on Jasem’s (lead developer) website.

Here’s a few more screens of the rest of the updated interface panels.

13 Panel Mosaic of the Moon


Yesterday, I had a few hours of clear sky, and got out my AVX along with my Celestron C5, and ZWO ASI224MC camera. I was determined to get a few shots of the moon. I initially tried a Powermate 2.5x, but the seeing just wasn’t there. I ended up shooting everything at prime focal length 1250mm.

I used Planetary Imager on the Mac to capture everything, then merged them all together in Photoshop using it’s photo merge feature.

Below you can see the individual frames that make up each part of the mosaic.

HD 14771 and Galactic Friends


I managed to produce a neat image over the last two nights. I centered the star HD14771 to place NGC 891 in the lower right and a galaxy cluster in the upper left. After two nights of imaging, I had around 13 hours. I placed it all together today. Turns out that the galaxy cluster was only a few of the total galaxies in this image. In all, there are 79.

Captured in EKOS/Kstars

Integrated with slight processing in Astro Pixel Processor

Completed processing in PixInsight and Photoshop

Overlay done in Observatory

Equipment used and shown in photo:
Imaging telescope or lens:Astro-Tech AT6RC
Imaging camera:ZWO ASI1600MM-Cool
Mount:Celestron Advanced VX
Guiding telescope or lens:Orion 60mm Guide Scope
Guiding camera:ZWO ASI224MC
Focal reducer:Astro-Physics CCDT67
Software:Astro Pixel Processor
Filters:Astrodon Tru-Balance Blue E-Series Gen 2 31mm, Astrodon Tru-Balance Green E-Series Gen 2 31mm, Astrodon Tru-Balance Red E-Series Gen 2 31mm, Astrodon Tru-Balance Luminance E-Series Gen 2 31mm
Accessory:MoonLite CSL 2.5" Focuser with High Res Stepper Motor

In this overlay, done in Observatory on the Mac, you can see all 79 galaxies highlighted.

In this overlay, done in Observatory on the Mac, you can see all 79 galaxies highlighted.

Here’s the scope that took the image. The AT6RC with CCDT67 reducer and ZWO ASI1600MM-C camera.

Here’s the scope that took the image. The AT6RC with CCDT67 reducer and ZWO ASI1600MM-C camera.