Starlight deflects as it grazes the sun, as the sun's mass warps space...so the vector momentum of a photon is altered by its encounter with the sun. But an altered momentum means that a force was exerted. So, does the starlight tug ever-so-slightly on the sun? Photons lack mass, so I suspect they don't warp spacetime...
In any event, this boils down to "if the sun exerts a force (momentum alteration) on a photon does the photon do the same to the sun?" My general relativity is so very poor- I suspect the answer may lie there.
This is a student question, and I'd be very grateful for any response you could share. Thanks!
david
David Ward
Professor of Physics
UNU# 3160
Dept. of Physics
Union University
1050 Union University Drive
Jackson, TN 38305-3697
office (731)661-5241
FAX (731)661-5175
dward@uu.edu