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...Switch to Plot a Different Celestial Coordinate Grid

Once you have set up a Plot to draw a coordinate grid ([*]), it is a simple matter to change things so that the grid represents a different celestial coordinate system. For example, after creating the Plot with astPlot, you could use:

astSet( plot, "System=Galactic" );
or:
astSet( plot, "System=FK5, Equinox=J2010" );

and any axes and/or grid drawn subsequently would represent the new celestial coordinate system you specified. Note, however, that this will only work if the original grid represented celestial coordinates of some kind (see [*] for how to determine if this is the case8). If it did not, you will get an error message.

For more information about the celestial coordinate systems available, see the descriptions of the System, Equinox and Epoch attributes in [*].


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AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council