1xy2sky(1)                   General Commands Manual                  xy2sky(1)
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Name

6       xy2sky - Compute RA Dec from X Y using WCS in FITS and IRAF image files
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Synopsis

9       xy2sky [-vbjg] [-n ndec] file.fts x1 y1 ... xn yn
10       or
11       xy2sky [-bdjgv] [-n ndec] file.fts @listfile
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Description

14       xy2sky (pronounced X-Y-to-sky) is a utility for getting the world coor‐
15       dinates of a set of image coordinates in a FITS or  IRAF  image.  World
16       coordinate system (WCS) information in the image header describes, in a
17       standard way, the relationship between sky coordinates and  image  pix‐
18       els. This information is used by the program to transform image coordi‐
19       nate (X,Y) pairs to right  ascension  and  declination  sky  coordinate
20       pairs. The current version of the program prints the coordinates at the
21       same equinox as is given in the image header, but future versions  will
22       allow transformations to B1950/FK4, J2000/FK5, or galactic coordinates.
23       Input and output files  in  the  Starbase  format  will  eventually  be
24       allowed.
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Options

27       -a     Append input line after output position
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29       -b     B1950 (FK4) output
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31       -d     RA and Dec output in degrees
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33       -e     Output in ecliptic longitude and latitude in degrees.
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35       -f <number>
36              Set third dimension for 3-D projections such as CSC
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38       -g     Galactic longitude and latitude output
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40       -i     First column is star id; 2nd, 3rd are x,y position
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42       -j     J2000 (FK5) output
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44       -m <number>
45              Set mode for output of LINEAR WCS coordinates:  0: x y linear 1:
46              x units y units 2: x y linear units units
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48       -n <number>
49              Number of decimal places in output RA seconds
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51       -q <year>
52              Output equinox if not 2000 (-j) or 1950 (-b)
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54       -t     Output as tab-separated table
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56       -v     More descriptive output -z Use AIPS classic projections  instead
57              of WCSLIB
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See Also

61       sky2xy(1)
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Author

64       Jessica Mink, SAO (jmink@cfa.harvard.edu)
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686 July 2001                        WCSTools                          xy2sky(1)