C+
C NAME:
C	ThomsonS10
C PURPOSE:
C	Convert to S10 units (Used internally only).
C CALLING SEQUENCE:
	function ThomsonS10(DSun,APM)
C INPUTS:
C	DSun		real	distance to Sun (in solar radii)
C	APM		real	apparent magnitude Sun at 1 AU
C OUTPUTS:
C	ThomsonS10	real	Conversion factor
C INCLUDE:
	include		'math.h'
	include		'sun.h'
C PROCEDURE:
C	If F is a flux in units of the flux incident from the solar
C	disk at heliocentric distance DSun, then R*F is the same flux in
C	S10 units.
C	The conversion is done in two steps:
C	1. Convert to units of the flux -incident- at r0 = 1 AU from the solar
C	   disk: multiply by (r0/DSun)^2
C	2. Convert to unit of flux from 1 10th magnitude star per square
C	   degree: multiply by (Pi/180)^2*10^((10-M)/2.5).
C	(Apparent magnitude, M=-2.5*log(Flux)).
C	Step 1 is needed because M is an apparent magnitude as observed at 1 AU.
C MODIFICATION HISTORY:
C	JUL-1996, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	    real	DSun
	    real	APM

	ThomsonS10 = MATH__RPD/(DSun*SUN__RAU)
	ThomsonS10 = 10**((10.-APM)/2.5)*ThomsonS10*ThomsonS10

	return
	end