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.