Star defects

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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StefanT
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Star defects

Post by StefanT »

Ivo,

I'm not sure, whether this is a ST-bug or not. Quite often stars in my images have coloured "edges" and/or "holes" as you can see in the following cropped image:
Image after initial auto-dev
Image after initial auto-dev
StarDefect-ST.jpg (281.6 KiB) Viewed 5676 times
If I take a look at the original FTS, the holes and edges are not there:
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StefanT
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Location: Siegen, Germany

Star defects - Part2

Post by StefanT »

FITS-Image as seen in FITS-Work
FITS-Image as seen in FITS-Work
NoStarDefect-FitsWork.jpg (156.63 KiB) Viewed 5675 times
This is how it looks in FITSWork. I don't have the slightest idea what goes wrong :confusion-shrug: - any idea?

The original file is available here
https://www.dropbox.com/s/9y5369fjirv5v ... ctTest.fit

Please excuse the bad image quality an the heavy CAs - I'm using old M42 lenses at the moment....
Thanks in advance - let me know if I can be of any help

Stefan
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admin
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Re: Star defects

Post by admin »

While I'm not sure how to replicate this, looking at the data, it seems that what appears to be saturated in the source image is not, in fact, completely saturated. There is color information there that can be recovered (and StarTools does so, while other software will happily destroy/desaturate it). The color information that is there seems to be anomalous though, possibly caused by misalignment, the chromatic abrration or somethingthat went wrong during stacking.
StarDefectTest.jpg
StarDefectTest.jpg (9.46 KiB) Viewed 5666 times
If you want to though, you can white out or overexpose the star cores by various means.
Ivo Jager
StarTools creator and astronomy enthusiast
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StefanT
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Re: Star defects

Post by StefanT »

Thanks, Ivo! I'll keep on investigating...
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