| imucac3
Find USNO UCAC3 Stars in Image Region
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imucac3 is a link to the
WCSTools
imcat
utility which finds all of the
U.S. Naval Observatory UCAC3 Catalog
objects in a FITS or IRAF image and lists their sky
and image positions. World coordinate system (WCS) information must be
present in the image header to describe, in a standard way, the relationship
between sky coordinates and image pixels.
This information is used by the program to find the region in the sky to
search and to transform right ascension and declination sky coordinate pairs
to image coordinate (X,Y) pairs. Output is sent to a file called
filename.uac and to standard output if the -v flag is set.
The UCAC3 number is the zone ((180 + 2 * declination in degrees) followed by
the sequence number of the star within the RA-sorted zone. This number
will change with each release of the USNO UCAC catalog.
Before you can use this program, the path to the directory containing the
region files must be set. The default is to use the value of the variable
ucac3path in the source code file libwcs/ucacread.c, which
is initially set to /data/astrocat/ucac3, which is where the catalog
resides at the Center for Astrophysics. If you do not have access to the
source code and need to change the path, you can set the environment variable
UCAC3_PATH to the directory containing the region files, and that
will override the file setting.
The minimum command line is
imucac3 FITS or IRAF filename
The same effect can be obtained by running
imcat -c ucac3 FITS or IRAF filename
Examples
- List the 10 brightest UCAC3 stars in a FITS image from a CDROM
- List the UCAC3 stars in a FITS image to a file
- Plot UCAC3 stars onto a FITS image
Last updated 18 November 2009 by
Doug Mink
