Used the JWST’s NIRCAM data (calibration level 3) from filters f444w-f470n, f335m, f227w, f200w, and f187n.

I tried to use the visible range filter too (f090w) but it was too artifacted even with extensive cleanup.

Processed in Siril using mostly the Veralux workflow scripts and a few scripts I made to wrangle JWST data.

I think I’m going to try the level 2 calibrated data next, it’ll be more work but I’ll also have more flexibility.

  • fraksken
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    28 days ago

    I love it! I also love your detailled description of the source data. Care to explain your workflow or point to some sources? I’d love to try this myself. (So much love)

    • kata1yst@sh.itjust.worksOP
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      27 days ago

      Certainly!

      The first step is to download Siril and then in the “get scripts” area download every Veralux script there is. These are nearly magic, fast, efficient, and the results are absolutely top notch.

      Once you have that, head over to the MAST portal and start hunting for data. The important part is to do an advanced search and add filters for mission: JWST, instrument: NIRCAM/image, data rights: public. You want to download only the files ending in “i2d.fits”- this is the level 3 calibrated data, which is the easiest to work with by far. Realistically you want to target data from 2025 or later, as before this the data they provided to the public was heavily artifacted.

      To find a target and limit my search I browse JWST releases and look for interesting pictures.

      Once you download the data (it’s massive) you’ll have to open the files in Siril, then immediately save the results as a new file. The reason is that the JWST files have a massive amount (literal GB) of scientific annotations in the FITS data. Amazing stuff, but we only want the picture. Without this step, the data won’t consistently open and save in the various scripts.

      Now for each image, step through Verilux Nox, Verilux Silentium, and Veralux Alchemy. Go slowly through the previews, as Nox and Silentium aren’t always needed on well calibrated JWST data.

      Next, you need to register, align, and stack the image into a color image. Guide here: https://siril.org/tutorials/rgb_composition/

      For colors follow this guide: https://jwst-docs.stsci.edu/files/216457506/216457541/1/1762454227819/multi_filter_plot_per_means_Jan2025.png and you can adjust later to make it look how you want.

      Then you’ll need to crop and rotate the image. This can be a little tricky, but the tool under the “geometry” menu entry is up to the task.

      Then you’ll do a plate solve: https://siril.org/tutorials/photometry/

      And (optionally, depending on how you like the results) you can try a Photometric Color Calibration to get the star colors accurate: https://siril.readthedocs.io/en/latest/processing/color-calibration/pcc.html

      Then you’ll want to extract the stars using StarNet (you’ll add them back with the Verilux workflow right before the end) https://siril.readthedocs.io/en/latest/processing/stars/starnet.html

      A very nice guide to the remaining steps and how to use all the Verilux scripts can be found here.(And the rest of the videos on his channel are gold for anyone learning Siril) https://www.youtube.com/playlist?list=PLJeHInlBzFrY8m5ATGJuSdXtWRH8SMFVJ

      Good luck!

      • fraksken
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        27 days ago

        This is great stuff! Thanks. I’ll dive into it tonight 😁