Online Astronomy Competition

The Online Astronomy Competition (OAC) is an international astronomy competition that tests students' knowledge in observational and theoretical astronomy. The competition consists of two main divisions: Open and Invitational. The Open division is accessible to all students worldwide, while the Invitational division is for top performers and features more challenging problems. OAC emphasizes practical astronomy skills including data analysis, celestial mechanics, and astrophysics.

2025
General
Problem 1 (105 pts)
Am I precessing?? (Or just tripping?) Invitationals
Problem 2 (90 pts)
Hijacking the Royal Swedish Academy of Sciences Invitationals
Problem 3 (85 pts)
Finding Riccardo Invitationals
Problem 4 (120 pts)
Among the stars Invitationals
Problem 5 (50 pts)
Wait, where are Ayush and Osish? Invitationals