The rigorous application of physics to understanding stars and stellar evolution, astrophysical sources of radiation, compact objects, and gravitational lensing. Topics include: gravitational dynamics; star formation, stellar structure and evolution; several radiative processes and phenomena such as blackbody, bremsstrahlung, synchrotron, Compton, inverse Compton, self Compton, dispersion, and Faraday rotation; special relativistic effects in astronomy such as Doppler shifts, aberration, and astrophysical jets; quantum effects in astronomy such as degenerate gases, hyperfine transition, and Zeeman absorption; gravitational lensing. Only one of PHYS 3350 or 4350 may be taken for credit. (Offered every other year.) Prerequisites: PHYS 1310 or 1312; PHYS 1305; PHYS 3323.