Jake wrote:
Please give the formulae for converting from celestial coordinates to
heliocentric.
Thanks.

Jake,
If you are an Einstein subscriber, and apply c=c+v to radar ranging of
the sun,(sic planets)
the astronomical unit varies up to 274,000kms whether measured at dawn
(radar approaching sun) or dusk (retreating).
Chances are, whatever replies you get on this, if so analysed will be
WRONG!

http://surf.de.uu.net/bookland/sci/farce/farce_6.html

Jim G
c'=c+v