GraXpert game changing freeware.

A number of weeks ago I stumbled upon a game changing piece of freeware, GraXpert. GraXpert's algorithm analyzes your deep sky image distinguishing stars and nebulosity from back ground sky and generates a background that eliminates gradients and reduces light pollution. A standalone app GraXpert is easy to use while offering settings that allow you to tweak the algorithm for better results. Prior to downloading this awesome piece of free software dealing with gradients, inherent to my  ASI294MC Pro was a bit tedious. With GraXpert you just load the stretched image*, create the grid, calculate the back ground and save the processed image. That's it. You can adjust the sensitivity of the grid creating algorithm to background intensity and you can move, add or delete grid points to distinguish nebulosity from the background. Aside from reducing my workload the colors in my images have improved. Some recent images follow. Thor's Helmet nebula was actually imaged from my 3rd floor balcony in my heavily light polluted south of Boston suburban skies with 120 15s sub exposures. 

*Stretching the histogram in Paintshop Pro seems preferable to the GraXpert stretching routine which seems to throw away black side data. 

Comet C2022E3 ZTF (2/15/2023)

Comet C/2022E3 ZTF  (2/8/2023)

Comet C2022E3 ZTF (1/30/2023)

Comet C/2022E3 ZTF (1/27/2023)

IC443, Sharpless 248, Jellyfish Nebula--Supernova Remnant. 

M42 Orion Nebula

M48 --Open Cluster

Flame Nebula (NGC2024) , NGC2023, Horsehead Nebula(B33)

NGC2264

NGC2353 Open Cluster

NGC2359 (Thor's Helmet Nebula)

M46(NGC2437) Open Cluster + Planetary Nebula NGC2437

NGC2232 Open Cluster

Messier 50 Open Cluster

Happy 2023 from the Terrace

The condo association gave me an early Christmas gift cutting down the sky obscuring dying tree outside my terrace. Trees across the way still block my light polluted skies. Nonetheless, I now have a descent strip of sky between 20 and 45 degrees altitude to work with during Orion season. I'll still make trips to my favorite darkish site in Harvard, MA but this will cut down on my carbon footprint as well as freezing toes during winter months. An additional benefit is access to WiFi allows me to monitor the scope using Chrome remote desktop. I'm pleasantly surprised with NGC2359 acquired with 15s subs which I first imaged with 60s subs last April from the McCoy's landing darkish site.  I'll definitely revisit NGC2359 between now and April from the terrace. 

The experiment with finder only All Star Polar Alignment has worked better than expected. Typically, I have only needed the two alignment stars plus two calibration stars after rough alignment with Polaris which is not visible from my south facing terrace. Typically less than 2 degrees of azimuth and less than 1 degree of altitude correction have been needed to correct for axis deviation from polar alignment. Thus far the Celestron AVX GoTo puts targets in the NightOwl  field of view (FOV). To center faint targets I just use Precise Goto which puts a bright star in the field which when centered in the FOV and centers the target with an offset.  Below are targets acquired on 12/27/2022 using 60x15s or 120x15s exposures.  Update: M42 reprocessed for reduced contrast and saturation.

M77 Irregular Galaxy

NGC 1788 Reflection Nebula

Left to Right: NGC2024(Flame Nebula), NGC2023, Horsehead Nebula (B33)

NGC2359 (Thor's Helmet) -- To be revisited

Orion Nebula (M42) again 😂

Recent Activity

I recently acquired a Celestron Motorfocus. What a great accessory. Aside from allowing more precise focusing there is no need to touch the scope (causing shake) or reposition one's self to access a focus knob. One can also enter previously determined number to get close to the focus for a particular optical configuration.  Cool. 

For the first time I visited one of my choice darkish sites it Maryland i.e. McCoy's Landing. It's not as dark as I had hoped thanks to increasing excessive LED street and security in nearby cities but it's better than trying to image from champion light polluter Frederick Maryland. The main target for the night was NGC2359 (Thor's Helmet ). The result below is a start that I hope to improve on when Canis Major returns in late 2022. Also, imaged that night were M48, M67, M81 and Sharpless 274.

NGC2359 (Thor's Helmet)

Messier 48

Messier 67

Messier 81 (Bode's Galaxy)

Sharpless 274