What is IAAC?
The International Astronomy and Astrophysics Competition is an educational astronomy competition open to students from around the world. In three rounds, students use their problem-solving skills and expand their knowledge through diverse astronomy and astrophysics problems. Since its launch in 2019, IAAC has reached over 28,000 students and involved 1,400 educators from more than 120 countries.
Who can participate?
Current high school and university students from all grades and countries are eligible. There are three age groups:
- Junior: 10th Grade and below (and < 16 years of age)
- Youth: 11th to 13th Grade (and < 19 years of age)
- Senior: 1st Year College/University and higher (or ≥ 19 years of age)
Depending on your age group, you will have to solve more problems to qualify for the next round: More Details. To solve the problems, you should be open-minded and creative. As some problems may require you to read real-world research material, fluency in English is beneficial. You should have a working internet connection to submit your solution online.
Prizes and Awards
Participating allows you to apply your astronomy skills to interesting problems and to learn about topics beyond the school curriculum. The top performers receive the 1st, 2nd, and 3rd prizes, with awards worth 1400 USD, including cash prizes and telescopes signed by astronaut Frank De Winne and Nobel Prize laureates François Englert, Gerard 't Hooft, Michel Mayor, and Didier Queloz. All participants receive participation certificates. There are also national awards for the best participants from each country: Prizes and Awards.
For Teachers and Schools
Teachers, schools, and parents are invited to share IAAC as an extracurricular learning opportunity for students with an interest in science. We provide learning materials, flyers and posters, and our team supports you with any issue. There are also special awards for teachers and schools: More Information.
Qualification Round
The Qualification Round is the first stage and consists of five astronomy problems. The problems in the Qualification Round encompass a wide range of topics, varying in difficulty and discipline. Some of the problems test your astronomy knowledge, others require calculations. Each problem gives 5 points, and to qualify for the Pre-Final Round in August 2025, you have to score at least 15, 17, or 20 points based on your age group.
Successful participants are honoured with certificates. Digitally typed solutions receive a special honorary note on the certificates: Prizes and Awards.
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Pre-Final Round
Qualified participants can register for the Pre-Final Round. The problems will be more challenging but also more engaging! You have four days to solve the problems, which include reading a real-world research paper. The Pre-Final Round consists of six problems that vary in difficulty, points, and subject: 2x Basic Problems (4 Points), 2x Advanced Problems (6 Points), and 2x Research Problems (8 Points).
All participants who are qualified and registered for the Pre-Final Round will receive the problems via email or via their participant account on Thursday, 14 August 2025. From that day on, you have until Sunday, 17 August 2025 to solve as many problems as possible. This year's registration costs are 11 EUR to fund the competition: Learn More (Registration Costs Flyer) (Financial aid is available to assist socio-economically disadvantaged participants.)
Final Round
Participants who have solved the Pre-Final Round successfully are qualified to participate in the Final Round: a multiple-choice online exam with 20 questions. The questions require knowledge of astronomy and astrophysics, as well as the content of the previous rounds.
The online exam is conducted in the participant's school, where a teacher supervises each Finalist. Alternatively, participants can also self-record their and upload the video. In this case, no teacher is needed. The awards and prizes are given to the Finalists with the most points in the Final Round. You can find more information about all three rounds here: Process and Rounds.