I found an answer in the archive of the forum, but from 2009. So I want to be sure.
I have to integrate photo emission to my BepiColombo simulation. Bepi can be at a location such that 0.3 < r < 0.47 A.U. If I follow this message:
“Message by Jean-Francois Roussel:
Yes,the norm of the vector defining the sun direction is used for that.
Norm = 0.1 => sun flux 10 time smaller than at 1AU, etc.”
For r = 0.3 A.U, I should do “sunDirection = 9” because flux varying in 1/r². Is it correct?