Public Data Repository

Hey folks!

I’m beginning to make all my AP data available publicly, under a CC BY-NC-ND 4.0 license.  It is located at

The repository currently contains all 2017 DSO data.  More will be added as time allows.

Should you create your own take on the data, I’d love to see your version!


Creative Commons LicenseThis work by Gordon Boulton is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Based on a work at

Posted in AstroImages, DSOs | Leave a comment

And then there was floor!

Well…subflooring, anyway. 🙂

Posted in Astroimaging Gear, ROR Obs 2.0 | Leave a comment

Handling SHO Magenta Stars in PixInsight

One of the most common complaints we hear when imaging narrow band targets is “How do I get rid of these bright pink/purple star halos in my SHO/Hubble palette image?”

In this video, I cover 3 simple methods to begin addressing this issue.

Posted in HowTo and Tutorials | Leave a comment

Narrowband NGC 7822 – Modified SHO

NGC 7822

Acquired 2017-09-26 - 2017-10-14 from TriStar Observatory TinyObs

28 x 900" Hα, 27 x 900" NII, 70 x 900" OIII, 40 x 900" SII : 41h 15m Total Integration

Stellarvue SV80ST

Astro-Physics Mach-1 GTO

Atik 414EX

Astrodon 1.25" 3nm Ha, NII, OIII, SII filters

QHY5-L II Guidecam

Sequence Generator Pro


Figured I’d try to throw in some NII for a change since…well…I have the filter, why not use it? Overall, not really worth the effort imo. It does show some VERY minor differences from the Hα signal in darker areas, but not enough to justify the several extra hours of imaging time.

Feel like I’m getting a better handle on taking narrowband images where I envision them when I first see the data. Color management is still a huge issue for me, and likely always will be, but I’m getting a better feel for “what makes a thing look like i think it looks”, so that’s a start anyway.

Not at all confident about the lower corners of this one. Very difficult for me to tell what’s nebula, what’s LP/noise gradient, and what’s just my imagination. The reddish corners are a “best compromise” result between “wow, the rest of the image looks nice but the corners are horrendous” and “might as well be monochrome”.

This is probably the last image for a bit. The Mach 1 has picked up a rather horrendous (and well out of spec) bit of PE and aberrant behaviour in the RA axis, and is currently sitting at AP’s shop for some troubleshooting and attention. When it returns, I may or may not throw it back in TinyObs, depending upon the completion level of Obs 2.0

Acquisition Details

  • Date and conditions
    • Acquired 2017-09-26 – 2017-10-14 from TriStar Observatory TinyObs
    • Bortle class 6-7
    • 28 x 900″ Hα, 27 x 900″ NII, 70 x 900″ OIII, 40 x 900″ SII : 41h 15m Total Integration
    • Equipment
      • Stellarvue SV80ST
      • Astro-Physics Mach-1 GTO
      • Atik 414EX
      • Astrodon 1.25″ 3nm Ha, NII, OIII, SII filters
      • QHY5-L II Guidecam
    • Software
      • Sequence Generator Pro
      • PHD2

Processing Details

  • All processing in PixInsight
    • Calibration of all light frames w/ 50-frame Dark masters, 200 frame Bias master, 50 frame Flat masters per filter
    • SubframeSelector to weight frames, (100 * SNRWeight)/(FWHM+Eccentricity). Frames w/ high eccentricity or FWHM rejected.
    • StarAlignment to register all frames
    • LocalNormalization applied using highest weighted frame from each set as reference
    • DrizzleIntegration x 2 of each filter set
    • RGB Processing
      • Masters cropped equally
      • DynamicBackgroundExtraction applied to each master, subtraction mode
      • Synthetic Luminence created using PixelMath
        • .8 * Ha + OIII + SII (Rescaling on)
      • MMT Noise Reduction applied to all masters
      • Masters stretched using HistogramTransformation to equal black points.
      • RGB Combination using PixelMath
        • .5 * Ha + .5 * NII to create HaNII
        • SII:HaNII:OIII
      • SCNR to Remove Green, amount .8
      • PixelMath for Magenta Removal
        R : $T[0]
        G : iif(min($T[0],$T[2])>$T[1],min($T[0],$T[2]),$T[1])
        B : $T[2]
      • MorphologicalTransformation through star mask to reduce stars in color master, using X/+ method
    • Lum Processing
      • Deconvolution through brightness mask w/ stars removed, using DynamicPSF & StarMask local support, 30 iterations
      • UnsharpMask through same brightness mask, Sigma 2.0, amount .8
      • MMT for very light NR through inverted brightness mask, heavily stretched.
      • MorphologicalTransformation through star mask to shrink stars, using round pattern, amount .15
      • DarkStructureEnhance script, about .4
      • HistogramTransformation to stretch SynthLum
    • Final Processing
      • LRGBCombination to combine SynthLum w/ RGB
      • CurvesTransformation to boost saturation, adjust colors via Hue.
      • Final light SCNR, amount .2







Posted in AstroImages, DSOs | Leave a comment

More progress on Obs 2.0

Floor framing got started today.  Had hoped to finish it today, but life conspired against me in the form of a dishwasher needing to be replaced.

Still, 1/3 or so was completed today. 🙂

Getting started on the floor framing.
Posted in Astroimaging Gear, ROR Obs 2.0 | Leave a comment

Obs 2.0 has a pier!

The pier for Obs 2.0 is poured. 🙂

There was digging.

Digging begins on the hole for the concrete pier.

And supervising

No work gets done around here without a supervisor.

And gravel

And concrete and rebar

Rebar went in at 6 and 12", alternating directions each layer.

SO much concrete

A half a freaking ton of concrete, one bag at a time!

Final stage was to build a "stub" for the pier, to hold the pier's rebar and tie the pier to the footer.

But alas there was a footer, awaiting a pier form.

The pier form began with some studs for a mounting board

At the side of the pier there will be a wooden plate, for mounting control boxes, power panels, etc.

And some conduit was added

Another 1/4 ton of concrete was mixed (We learned from last time!)

And poured

Mounting plate bolts were set

24 hours later, the form came off!


Posted in Astroimaging Gear, ROR Obs 2.0 | Leave a comment

Totality is life-changing

10 frame composite of totality from Hopkinsville, KY

I stood there, in a cornfield in Hokinsville, KY.  I thought the day had been exciting, waiting for and then observing the steady march of the moon’s disc across the Sun.  One of the children there described it as the Sun being eaten. The light around us took on a rather eerie and disquieting “emptiness”…indeed, as though it were being eaten.

And then it happened.  Totality.  It struck me like a ton of bricks…the buildup had been nothing.  THIS was “the show”.

I must have started my camera sequence…it ran.  I quite literally don’t remember doing it.  It was 10 minutes later before I even remembered to wonder if I had.

I found myself lying on the ground, staring up at totality…I don’t remember laying down.

I knew, somehow, that my life had changed.  The very fabric of what it meant to me to be human had become, somehow, tangible and real.  It took me days to understand why.

Man’s distinctive characteristic is his type of consciousness—a consciousness able to abstract, to form concepts, to apprehend reality by a process of reason.  – Ayn Rand, Introduction to Objectivist Epistemology

Rand, as she so often had, provided the words I was unable to find on my own.

The birds went quiet, the dogs settled, the nocturnal bugs began their night-time calls and dances.  To the entire world, it was night.

Save for the Men.

As Man, we understood.  It was not night.  It was the chance alignment of orbiting bodies, behaving as they must in accordance with the laws of nature.  Laws we cannot directly observe with any of our senses, but which must, nevertheless, be.  Only our ability to “abstract, form concepts, and apprehend reality by a process of reason” allows us to know them, to understand their nature, and to know that this place, at this time, on this day, would allow us to observe their effects on the world around us.

Why was I there?  Simple.

I reject any philosophy, any spirituality, any code, or any mysticism that dare suggest to me that knowledge of the world around me is a sin.

The function of my rational mind is what makes me Man, and connects me with the universe in which I live, and allowed me to experience this moment.

I’ll allow nobody to take that away.

Posted in AstroImages, Random Sciency Stuffs, Solar System | Leave a comment

Eclipse stuff!

So yeah, unless you live under a rock, you know there’s a total solar eclipse coming in a couple weeks, and you probably know we’re in the path of totality.  You may even have done some googling or read a bit about “totality’, and what a “total solar eclipse” means.

(If not, this page has a pretty good explanation of the types of solar eclipses, and the differences between them.)

SO…this post won’t bore you with all that crap. 🙂

Instead, I want to tell you about a few “odd” things you may, if you’re lucky, get to experience during this total eclipse, before, during, and after totality.

If there’s some trees nearby, during the partial phases of the eclipse, go stand in their shade and look at the bits of light coming through the leaves.  At the right orientation, you may be able to see thousands of tiny “crescent suns” on the ground!  This is the result of the tree’s leaves…and more specifically the small gaps between them…acting as pinhole cameras!  In precisely the same way as we MAKE pinhole cameras for viewing the partial portions of an eclipse, nature has provided her own. 🙂

If you can find a wide open, flat area for viewing the eclipse, pay close attention to your surroundings in the few moments before and after totality…you may actually be able to watch the moon’s shadow rushing across the ground toward and away from you.

During totality, the sky will become dark enough to see several bright planets and even a few stars.  Especially look for two bright “stars” fairly near the sun…those are likely to be Venus (farther away, west of the sun, and the much rarer sight, Mercury (which should be quite close, slightly SSE of the sun).  You may also catch sight of the star Sirius.

Also during totality, take your eclipse glasses off (Yes, it’s COMPLETELY safe to do so during totality) and if we get REALLY lucky (not, I’m afraid, very likely as this eclipse is occurring during a solar minimum) not only will you be able to see the sun’s corona (the pale “glow” around the sun during this time…essentially the sun’s atmosphere) but you may be able to see bright red prominences at the edge…a sight normally reserved only for specialized solar telescopes and filters.

And finally, immediately (as in, within a minute or so) before and after totality, look on light colored surfaces (perhaps a bit of poster board facing the sun, the side of a house or car, etc) for “wavy shadows”.  As the moon is very near complete coverage of the sun’s disc, the turbulence of the atmosphere combined with gaps/holes/barriers created by the rough, mountainous edge of the moon’s disk will produce a very strange effect, and you’ll see shadow’s dancing and waving across lightly colored surfaces.

Ultimately, remember first and foremost to BE SAFE.  but don’t forget to experience all the fascinating and unique sights such a rare astronomical event has to offer.

Posted in Space News | Leave a comment

IC 1396 : The Elephant’s Trunk Nebula in Narrowband – Modified SHO Palette

Feel pretty good about this one.  Decided to go for a nice big bright object this time, for a little “relaxation”.

The Elephant’s Trunk is an area of active star formation in the constellation Cepheus, some 2,400 LY away.

The “trunk” itself is a large globule of dense dust, with a bright “surface” being ionized by the large star HD206267, the bright star “above” the trunk in this image.

The hole in the “top” of the trunk is the home of 2 young stars which have cleared out the dust and gas with their stellar winds.

* Acquired 2017-07-29 - 2017-07-31 
* 16 x 900" each Ha, OIII, SII : 12hr Total Integration
* Stellarvue SV80ST
* Astro-Physics Mach-1 GTO
* Atik 414EX
* Astrodon 1.25" 3nm Ha, OIII, SII filters
* QHY5-L II Guidecam
* Sequence Generator Pro
* PHD2


Posted in AstroImages, DSOs | Leave a comment

New PixInsight Tutorial : Creating Mosaics with a simple StarAlignment and GradientMergeMosaic workflow.

I’m generally not known for my image processing prowess. (Quite the opposite in fact…if I’m known at all, it is for my ability to murder perfectly innocent data in the prime of its life.)

Every so often, however, I manage to wrap my brain around a particular process or concept in PixInsight.  I seem to have a knack for making mosaic panels get along and play well with each other.

To this end, I offer a simple, repeatable, and relatively straightforward process for creating mosaics in PixInsight.


Posted in HowTo and Tutorials | Leave a comment