This SAOimage display shows the alignment of
GSC-ACT stars with a test image after a
world coordinate system has been fit. The coordinates plotted are based
on header keywords describing a plane-tangent system fit by matching HST
Guide stars and sources found in the image.
This image was produced by a one-line Unix shell script for this task,
saoimage -reg `imgsca -r 15 $1` -wcscom sgsca_-ha_%s $1where the argument to the task is the name of the file to be displayed.
The immatch program can provide a list of the stars in the image which match catalog stars.
|Click on the image for full-screen view|
imgsca finds all of the
GSC-ACT stars in the image based on
the world coordinate system parameters in its header and writes them to the
seen on the right.
The name of this file is sent to standard output which the backquotes give to SAOimage as a command line argument following the -reg command.
# HST Guide Stars/ACT (15" radius) CIRCLE(662,660,23) # gscact 2580.1696 CIRCLE(738,763,23) # gscact 2580.1207 CIRCLE(960,977,23) # gscact 2580.1403 CIRCLE(284,620,23) # gscact 2580.2291 CIRCLE(529,33,23) # gscact 2580.1629 CIRCLE(210,866,23) # gscact 2580.1158 CIRCLE(527,446,23) # gscact 2580.1710 CIRCLE(948,475,23) # gscact 2580.1798 CIRCLE(33,920,23) # gscact 2580.2147 CIRCLE(900,395,23) # gscact 2580.1909 CIRCLE(818,653,23) # gscact 2580.1943 CIRCLE(589,525,23) # gscact 2580.1485 CIRCLE(231,195,23) # gscact 2580.1878
sgsca 2.9.4, 29 June 2001, Doug Mink SAO Find closest star gscact 16:15:56.155 +31:24:24.82 J2000 r= 900.00 at epoch 2000.00 GSC number RA2000 Dec2000 Mag Class Band N Arcsec 2580.1710 16:15:56.110 +31:24:24.26 14.13 3 14 1 0.80