Astrophysics is a branch of astronomy. Astrophysicists study and analyze the physical interactions between objects in the Universe. The properties of black holes, stars, galaxies and other large structures in the cosmos are studied by those with a Ph.D. in astrophysics. Astrophysics is either observational astrophysics or theoretical astrophysics. Earning a Ph.D. in astrophysics is an extremely challenging endeavor. Prospective students must maintain superior academic performance throughout high school and college, especially in mathematics and the physical sciences. Obtaining a Ph.D. usually requires three to five years of additional study after college graduation.

Step 1

Earn a bachelors degree in a field related to astronomy and astrophysics. A bachelors degree usually requires four years of college. Some universities require a minimum number of undergraduate school credit hours devoted to mathematics, physics and astronomy. An excellent grade point average of at least 3.5 will increase the likelihood that a you will be accepted into a program.

Step 2

Take the Graduate Record Examination (GRE) general examination and the GRE physics examination. Each Ph.D. program may have different minimum GRE score requirements. A school's admissions counselor can advise you about minimum test score requirements. The higher your GRE score on the physics examination, the better your chances of being accepted in a Ph.D. program.

Step 3

Pass the required core physics and astronomy coursework after admission to a Ph.D. program. Coursework usually takes two years to complete. Most universities require a minimum grade point average of 3.5 to pass, but individual classes may require a higher grade to pass. These classes are extremely difficult and require a lot of study time. Ph.D. students must dedicate themselves to the program if they are to succeed.

Step 4

Complete a research project, and write a dissertation (if required by the university Ph.D. program). Research projects must be approved by the faculty of the Ph.D. program. The research project may require as little as one year or take as long as five years to complete. Once complete, the project will be reviewed and graded by a panel of graduate program faculty members and one faculty member from a different discipline.