Image integration date with defraction spikes

Ian Hudson

HI

I have a lot of data, about 1500 LRG&B frames (calibrated, registered, Normalized Scale Gradient) of a galaxy without star defrraction spikes.

I also have a lesser amount, about 300 LRG&B frames, of the same galaxy with star defraction spikes.

Am I going to loose the defraction spikes if I integrate the data together ?  or would I be better to combine 2 seperately integrated images with PixelMath and if so would 'combine(1stimage, 2ndimage,op_screen())' be the right formula?

Thank you

Ian

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BlockHead

Yes, you would lose the diffraction spikes (and I think you should!).

However, if you want to keep the diffraction spike STARS... the whole thing the star and the spikes.

1. Integrate everything and lose the spikes. This is the full data.

2. Integrate ONLY the data with the stars that have the spikes.

3. Remove the stars from the above with StarExterminator. You might want to stretch the image to the degree you would like them to appear in the final image. Do this before SXT.

4. Now throw away *all* stars in the full stretched data.

5. Put the diffraction stars into the starless full data image.

Is this what you are looking for?

-the Blockhead

Ian Hudson

Thanks Adam

I appreciate your help (even though you are not a fan of spikes).  I was contemplating my question while waiting for some guidance and thought "I wonder if StarExterninator would do the job".

That's exactly what I looking for, thank you.

Ian