How can get phd in stellar physics, l live in Iraq?

my work are focused on nuclear fusion reaction in the star, and on the process of providing this energy. Where the sun undergoes major changes in its structure, which can calculating by using a solar model means the determination of density, pressure, temperature and luminosity as a function of m or radius through hydrogen burning because most of the energy is released by the conversion of hydrogen into helium, using Fortran-77 program.