---
name: "imgsc"
section: "1"
platform: "linux"
package: "wcstools"
version: "3.9.7-1.1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/imgsc"
---

# imgsc(1)

Find HST GSC stars in FITS or IRAF image files

## Name

imgsc - Find HST GSC stars in FITS or IRAF image files

## Synopsis

imgsc \[options\] FITS or IRAF file(s)

## Description

Search the HST Guide Star Catalog within the area described by the world coordinate system in an image header.  This is a link to imcat rather than a separate executable.

## Options

- **-b \[\<RA\> \<Dec\>\]**

  Output in B1950, optional new image center in B1950 (FK4) RA and Dec

- **-c \<name\>**

  Reference catalog (gsc, ujc, or tab table file

- **-g \<class\>**

  Guide Star Catalog class (-1=all,0,3 (default -1)

- **-h**

  Print heading, else do not

- **-j \[\<RA\> \<Dec\>\]**

  Output in J2000, optional new image center in J2000 (FK5) RA and Dec

- **-m \[\<bright magnitude\>\] \<faint magnitude\>**

  Limiting catalog magnitude(s) (default none, bright -2 if only faint is given)

- **-n \<num\>**

  Number of brightest stars to print

- **-p \<scale\>**

  Initial plate scale in arcsec per pixel (default 0)

- **-s**

  Sort by RA instead of flux

- **-t**

  Tab table to standard output as well as file

- **-v**

  Verbose listing of processing intermediate results

- **-w**

  Write tab table output file imagename.cat **-z** Use AIPS classic projections instead of WCSLIB; use CD matrix or CDELT instead of polynomial solution.

## See Also

imcat(),imuac(),imusac(),scat()

## Author

Jessica Mink, SAO (jmink@cfa.harvard.edu)