ASTSCRIPT-PSF-SELECT-STARS(1)

✨ astscript-psf-select-stars — the star-picking queen 👑💫

okay bestie, so this is the manual page for astscript-psf-select-stars, living in the User Commands section of the GNU Astronomy Utilities docs. she's a script, she's a diva, she finds you stars. let's get into it 🫶

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🌸 NAME 🌸

astscript-psf-select-stars — select good stars for constructing the PSF

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🎀 SYNOPSIS 🎀

astscript-psf-select-stars [OPTIONS] image.fits

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🦋 DESCRIPTION 🦋

so the whole point, the entire mission, the moment: this builds you a catalogue of "good stars" that you're gonna use to construct an extended and non parametric PSF. and when we say "good stars" we mean stars that literally do not have close objects messing with their surroundings — so they're not contaminated. clean. pristine. main character stars only ✨

and here's the cute part: if you don't hand her another catalogue, she'll just go ahead and build a catalog of stars from reference datasets (Gaia) for you. she's got you fr fr 💅

on top of that, other parameters get considered too — like the axis ratio — to filter the sample down and keep only the proper stars. vibe check passed or you're out, no cap.

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⭐ astscript-psf-select-stars options: ⭐

💖 Input:

• -h, --hdu=STR/INT — HDU/Extension name or number of the input file.
• -S, --segmented=STR — segmentation file, the one you got from Segment (astsegment).
• -D, --dataset=STR — query dataset (gaia --dataset=edr3, etc.).
• -r, --racolumn=STR — Right Ascension (R.A.) column name.
• -d, --deccolumn=STR — Declination (Dec) column name.
• -f, --field=STR — magnitude column name (phot_rp_mean_mag, for Gaia).
• -p, --parallaxanderrorcolumn=STR,STR — the name of the parallax column.
• -m, --magnituderange=FLT,FLT — the range of magnitude.
• -Q, --minaxisratio=FLT — minimum axis ratio to be accepted (defaults to 0.9).
• -M, --mindistdeg=FLT — minimum distance to more bright neighbor stars to be accepted, in degrees.
• -c, --catalog=STR — catalog of stars containing: ra, dec, magnitude, parrallax, parrallax_error.
• -a, --matchaperturedeg=FLT — aperture, in pixels, to match catalogue ra and dec coordinates with clumps' ra and dec.
• -F, --faintmagdiff — the difference from the faintest star which the user will be determined the faintest star in the --magnituderange option.
• -b, --brightmag — the limit for selecting a wider range of bright stars.

🌈 Output:

• -o, --output — output table with the object coordinates.
• -t, --tmpdir — directory to keep temporary files.
• -k, --keeptmp — keep temporal/auxiliar files.

🧚 Operating mode:

• -h, --help — print this help.
• --cite — BibTeX citation for this program.
• -q, --quiet — don't print any extra information in stdout.
• -V, --version — print program version.

heads up bestie: any argument that's mandatory or optional for a long option is also mandatory or optional for the corresponding short option. same energy, shorter name 💅

GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/

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😭 REPORTING BUGS 😭

found a bug? tell the girlies at bug-gnuastro@gnu.org. do NOT suffer in silence, that's not the vibe 🙈

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💀 COPYRIGHT 💀

Copyright © 2020-2025 Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.

this is free software: you are free to change and redistribute it. and just so we're clear — there is NO WARRANTY, to the extent permitted by law. like, none. zero. nada. periodt.

Written/developed by Sepideh Eskandarlou. ate and left no crumbs 👑

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🌟 SEE ALSO 🌟

the full documentation for astscript-psf-select-stars is maintained as a Texinfo manual. if the info and astscript-psf-select-stars programs are properly installed at your site, the command

info astscript-psf-select-stars

should give you access to the complete manual. iykyk 🎀

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GNU Astronomy Utilities 0.24 — November 2025 💜

and that's the whole page bestie, tysm for reading, go select some iconic little stars 🦋✨💖