Imaging point sources with the gravitational lens of an extended sun

We study the optical properties of solar gravitational lens (SGL) while treating Sun as an extended, axisymmetric and rotating body. The field is represented using a set zonal harmonics. develop analytical description intensity light that observed in image plane strong interference region realistic SGL. This formalism makes it possible to model not only point-spread function point sources, but also actual observables, images form focal imaging telescope positioned plane. Perturbations monopole are dominated by quadrupole moment, which results forming astroid caustic on Consequently, placed inside observes four bright spots, well-known pattern Einstein cross. relative intensities positions these spots change moved plane, with merging into arcs when approaches boundary. Outside caustic, two remain eventually becomes indistinguishable from at greater distances axis. present extensive numerical simulations, basis our ongoing prospective exoplanet These applicable describe large class lensing scenarios involving lenses can be