imstar(1)

🌟 NAME 🌟

okay so bestie, gather round 💖 the command we're talking about is imstar — it's the girl whose whole job is Find stars in FITS and IRAF image files. like she literally goes into your image and picks out the stars. main character behavior, no cap ✨

🎀 SYNOPSIS 🎀

imstar [options] [FITS or IRAF filename] or [@file of image file names]

so you give her options, then either a FITS or IRAF filename, or an @file of image file names if you're feeling extra and wanna do a whole list at once 🦋

💅 DESCRIPTION 💅

ngl the original page leaves this bit blank — it's giving "saved a seat but nobody came" 😭 so we're just gonna move straight to the good part. the options. the whole menu. periodt.

✨ OPTIONS ✨

first up, the little coordinate situation at the top (she's not a flag, she's a mood):

• <hh:mm:ss> <dd:mm:ss> [J2000, B1950] — Coordinates for center (or reference pixel if -x is used). so like, where you want the middle of things to be 🫶

and now the flags, one by one, no skipping, we're not doing that here:

• -a <angle> — Image rotation angle in degrees (default 0). If it's a multiple of 90, she rotates the image before the search and sets the WCS angle to zero; if it's not, it goes in the WCS. cute, right? 🌸
• -b — Output B1950 (FK4) coordinates (default=image equinox). old-school coords, vintage aesthetic 💜
• -d <catalog name> — Read this DAOFIND style catalog of X, Y, and magnitude instead of searching for stars in the image. The format is simply white-space-separated numbers on a line, with # at the beginning of comment lines. so you bring your own list and she just reads it 🙈
• -e <num> — Number of pixels to ignore around image edge. edges are messy, we're ignoring them ✨
• -f — Write a simple ASCII catalog file instead of tab table or DAOFIND format (number RA DEC mag ... per line, with two lines of header info). plain text, no drama 🎀
• -h — Print heading, else do not. tiny flag, big energy 👑
• -i <num> — Minimum peak value for star in image (<0=-sigma). Setting this to reject all but 10-15 stars is a good way to speed up the star-finding process. If num is less than zero, the minimum peak is -num image pixel standard deviations. Setting this number rejects faint stars early in the selection process for a significant saving in computing time. basically: be picky, go fast 🔥
• -j — Output J2000 (FK5) coordinates (default=image equinox). the modern era 💅
• -k — Print each star as it is found for debugging. she's narrating. let her 🦋
• -l — Reflect the image left <-> right before rotating (-a) and searching for stars. mirror moment ✨
• -m <magnitude> — Magnitude offset. nudge nudge 🌈
• -n — Number of brightest stars to print. only the icons, only the headliners ⭐
• -o — Output star list in DAOFIND format. The first three numbers on each line of the output file are X, Y, and magnitude, separated by one or more blanks or a tab. Lines beginning with # are ignored. iykyk 💖
• -p <num> — Plate scale in arcsec per pixel (default 0).
• -q <c|d|o|s|x|v|+> — Output region file shape for SAOimage (default o). Characters mean: c>ross, d>iamond, s>quare, o>circle, x=X, v>ary with GSC type, +>cross. pick your shape, pick your vibe 🎀
• -r — Maximum radius for star in pixels. keep it contained bestie 💜
• -s — Sort by RA instead of flux. alphabetical-ish, but for sky ✨
• -t — Output in Starbase tab table format.
• -v — Verbose listing of processing intermediate results. she's telling you everything 💀
• -w — Write output to a file in addition to standard out. If DAO format (-o), create the name by adding .dao to the image file name. If Starbase format (-t), create the name by adding .tab to the image file name. If ASCII format (-f), create the name by adding .stars to the image file name. she's keeping receipts AND telling you 🫶
• -x <X> <Y> — X and Y coordinates of reference pixel (if not in header or image center). for when the header's being unhelpful 😭
• -z — Use AIPS classic projection code (for "-SIN", "-TAN", "-ARC", "-NCP", "-GLS", "-MER", "-AIT" and "-STG" only) instead of WCSLIB proposed standard projection code. classic vs. proposed, choose your fighter 🌸

🌈 WEB PAGE 🌈

http://tdc-www.harvard.edu/software/wcstools/imstar/

go look, she has a whole website, iconic 👑

💖 AUTHOR 💖

Jessica Mink, SAO (jmink@cfa.harvard.edu) — the actual legend behind this whole thing, we stan 🌟

and that's the whole page, bestie 💅 that's imstar, 6 July 2001 edition, part of the WCSTools family, section imstar(1) — literally all of it, nothing skipped, no cap 🎀✨🦋