USA Astronomy and Astrophysics Olympiad (USAAAO)

The USA Astronomy and Astrophysics Olympiad (USAAAO) is the national competition that selects the U.S. team for the International Olympiad on Astronomy and Astrophysics (IOAA). It runs three proctored rounds across the year: a multiple-choice First Round, the free-response National Astronomy Competition (NAC), and a two-part theory-and-practical Third Round. The competition follows the IOAA syllabus, covering positional astronomy, celestial mechanics, photometry, stellar and galactic astrophysics, and cosmology. Top performers are selected for online training and the final team chosen to represent the United States at the IOAA.

Top 15 eligible NAC scorers join online training and take the Third Round; the top five are selected to represent the United States at the International Olympiad on Astronomy and Astrophysics (IOAA).

Anyone may take the First Round. Only high school students who are U.S. citizens or permanent residents are eligible to be selected for the US IOAA team, subject to IOAA age and grade limits.

Register for the First Round (registration opens in January); score above the First Round cutoff to reach the NAC; top NAC scorers (top 15 eligible) progress to online training and the Third Round; final team selected by weighted NAC/Third Round scores.