I was wondering if the "sun symbol" issue could have been solved by
anyone.
It's been a while that I try to make it work using hardware font for
postscript device (e.g. D. Fanning's ps_start, font=0). The solutions
for this kind of font available on google (e.g. ps_frag.pro, changing
the unicode in /itt/resources/fonts/, etc) are notvery satisfactory
because not quite user-friendly...

So, if a good solution has been found, please let me know! ;)

I know there are routines people have used, but I'll let people more
familiar with them tell you about their favorite.

   http://idlastro.gsfc.nasa.gov/ftp/pro/plot/sunsymbol.pro

available from the IDL Astronomy User's Library
(idlastro.gsfc.nasa.gov). You might want to just get there entire library.

 http://michaelgalloy.com/wp-content/uploads/2011/01/vis_psfrag.pro

although this is not yet a drop-in solution.

Actually, sunsymbol.pro has off-center sun symbol as you say, and
vis_psfrag.pro is not very easy to handle (especially because it
replaces the full string by the sun symbol as far as I understand...).

So, no sun symbol solution yet for postscript fonts in IDL7.1...
Thanks though.

1. Generate your plot in PS with the /TIMES switch and !P.FONT=0
2. Run ms_psfrag with this syntax:

ms_psfrag,input_ps_filename,latex_template_filename,output_ps_filename,"act ual
text in the ps","replacement latex text"

You will have to download ms_psfrag.pro (here:
http://astro.phy.vanderbilt.edu/~sinham/code/ms_psfrag.pro). Also, you
have to create a Latex template file -- the contents for the latex
template are in the comments on the top of ms_psfrag.pro.

I still haven't figured out how to sent the font size correctly so you
will have to play around with this line in the latex template:

\psfrag{tag_text}[c][c][1.5]{replacement_text} ,

where 1.5 represents the font size scaling. You will have to change
that 1.5 value such that the replacement font size is similar to other
font sizes in the plot.

For the solar mass symbol, the latex replacement text would be '$M_
\odot$'. A code snippet could be:

-----------------------
set_plot,'ps'
!p.font=0
fname = 'plot.eps'
templatefname = 'figure.tex' ;;;; you will have to create this latex
template file as figure.tex
device,filename=fname,/color,/portrait,bits_per_pixel=8,/encapsulated,/
times
xtitle = 'ZM'

plot,findgen(10),xtitle=xtitle

device,/close
outfname = fname
ms_psfrag,fname,templatefname,outfname,xtitle,'Mass [M$_\odot$]'
-----------------------

Hope this helps.