To get an accurate conversion of solar system objects direction to a celestial frame, one should convert to AZEL or HADEC before to get parallax accounted for. Thus if you want to get the moon's position in J2000..one would do it in 2 stages\\
<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/tools/xml/casa.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://casa.nrao.edu/schema/psetTypes.html">
<tool module="measures" name="measures">
<shortdescription>measures tool</shortdescription>
<keyword>measures</keyword>
<include>measures_forward.h</include>
<include>measures_private.h</include>
<method name="measures" type="constructor">
<shortdescription>Construct measures tool</shortdescription>
<returns type="measures"/>
Create a measures tool on the specified host (or by default the
host you are running on).
<method name="dirshow" type="function">
Show direction measure as a string.
<param name="v" direction="in" type="record">
<description>a direction measure value to be converted to string
dirshow will convert a direction measure to a string
print "\t----\t dirshow Ex 1 \t----"
print me.dirshow(me.direction('venus'))