Format
The IOAA is organized annually in a different host country, which shall cover all costs with every team during the event (includin lodging, food, excursions, awards, etc.). Having no registration fee, the participating countries shall only cover the expenses for its own team to arrive at the host place.
Each participating country sends one regular team with up to five (5) high school students (or students who finished their high school within the year of the competition), accompanied by two team leaders, normally scientists or teachers. In addition, the host country has the right to send one additiona, guest team.
Read more about this topic: International Olympiad On Astronomy And Astrophysics