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Old October 26th 11, 09:39 PM posted to sci.astro.research
Steve Willner
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Default Tales of Cataloguing II

In article ,
Phillip Helbig---undress to reply writes:
The difference between B1950 and J2000 is not due just to the precession
of the equinoxes.


There are some differences at the arcsecond level because of the
updated reference frame (now based on quasars with VLBI positions),
but is there anything else?

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