What's New

2026 Astronomy Contest Dates

We’ve made some changes to the 2026 competition dates and rules. Please see the description under each competition and the contest dates for the current academic year.

CAAO Senior

The length of the CAAO Senior has changed from one week to one day. We will adjust the difficulty of the questions accordingly.

Date: Saturday, March 14, 2026

CAAO Junior

The length of the CAAO Junior has also changed from one week to one day. We will adjust the difficulty of the questions accordingly.

Date: Saturday, May 23, 2026

The detailed registration and test-writing instructions will be posted a few weeks prior to the contest dates.

CAAO Senior Camp

The training camp is for students who have performed well on the CAAO Senior. The IOAA team will be formed based on students’ CAAO and camp exam results.

Date: May 29–31, 2026. This date is subject to change depending on the location availability.

2025 Team Canada IOAA Results

Congratulations to Team Canada on its outstanding performance at the 18th IOAA held in Mumbai, India. Our team returned with silver and bronze medals.

2025 CAAO Jr. Results

The results for the 2025 CAAO Jr. has been posted here.

The top ten students on the CAAO Jr. 2025 are also selected for Team Canada to compete at the IOAA Jr. in Romania.

2025 CAAO Results

The results for the 2025 CAAO has been posted here.

2024 Team Canada IOAA Jr. Results

Congratulations to Team Canada on its outstanding performance at the third IOAA Jr held in Kathmandu, Nepal. Our team returned with a gold medal and an honourable mention.

This is Team Canada's first participation in the IOAA Jr. The remarkable results of our participants will pave the way for new students to push the boundaries of their aspirations.

2024 Team Canada IOAA Results

Congratulations to Team Canada on its outstanding performance at the 17th IOAA held in Rio de Janeiro, Brazil. Our team returned with gold and bronze medals.

Their collective effort has truly showcased the talent Canada brings to the international stage, and each one of them deserves our admiration and gratitude.

New Partners and Sponsors

We would like to express our sincere appreciation to McMaster University's Planetarium for their generous support. Your support is essential to help us bringing astronomy and astrophysics education to more students across Canada.

2025 Astronomy Contest Dates

This year, we’ve made some changes to the 2025 competition dates and rules. Please see the description under each competition and the contest dates for the current academic year.

CAAO Senior

The format of the CAAO Senior is similar to that of last year. We will make some adjustments to the question types.

Date: March 9­­­­–16, 2025

CAAO Junior

We will introduce a new Olympiad competition for students aged 15 and under. This is the team selection exam for the IOAA Jr. competition.

Date: May 24–31, 2025

CAAO Senior Camp

The training camp is for students who have performed well on the CAAO Senior. We have moved the date of the camp to May 2025 as well. Unlike last year, the IOAA team will be formed based on students’ CAAO and camp exam results.

Date: May 30–June 1, 2025. This date is subject to change depending on the location availability.

2023 Team Canada IOAA Results

We are thrilled to announce Team Canada's returned from the 16th IOAA held in Chorzów, Poland, decorated with three medals: gold, silver, and bronze.

Their collective effort has truly showcased the talent Canada brings to the international stage, and each one of them deserves our admiration and gratitude.

Results of the 2024 Canadian Astronomy Olympiads

• Canadian Astronomy Competition "Aurora Borealis" (CAC).  The results for the top six contestants have been posted here.

• Canadian Astronomy and Astrophysics Olympiad (CAAO). The results for the top contestants have been posted here.

CAAO Junior 2025

The CAAO Jr. is now available to download.

Books, online resources, and calculators are allowed.

Collaboration with others, posting on forums, or paying for external help is strictly prohibited.

A confirmation email will be sent out once we receive the contest. If you don't receive a confirmation within a day after submission, please let us know.

CAAO Jr. 2025

The Canadian Astronomy and Astrophysics Olympiads Junior (CAAO Jr.) 2025 are scheduled to commence on Saturday, May 24 at 12:00 PM ET (9:00 AM PT). The contest will be posted on this website at that time.

All participants are required to register for the competition. A registration fee of $20 applies. Please e-transfer the registration fee to payment@caao.ca.

Students can register by sending an email to info@caao.ca with the following information:

- First and Last Name

- Grade

- School Name, City, Province

- Date of Birth

- Citizenship Status

- Email for Contact

To prove that you’ve made the payment, take a screenshot and write in the e-transfer message: This is the CAAO payment for [student name]. Attach the payment proof in the registration email.

Students have time to register until the end of the competition, which is on Saturday, May 31, at 12:00 PM ET (9:00 AM PT).

Participants will have one week to complete the contest and submit their handwritten solutions to info@caao.ca. We would like to remind participants that typed-up solutions will NOT be accepted.

The deadline for the submission of CAAO Jr. solutions is at 12:00 PM ET (9:00 AM PT) on Saturday, May 31. We encourage all interested students to take part in this Olympiad competition and showcase their knowledge in astronomy and astrophysics. The Canadian IOAA Jr. team will be chosen from the top students from the CAAO Jr. This year, the IOAA Jr. will be held in Piatra-Neamt, Romania from October 18 to 25, 2025.

Students from any country can participate in the CAAO Jr. However, only Canadian citizens or permanent residents will have the opportunity to represent Canada at the international Olympiads.

We wish all participants the best of luck in the CAAO Jr.

CAAO 2025

The CAAO is now available to download.

Books, online resources, and calculators are allowed.

Collaboration with others, posting on forums, or paying for external help is strictly prohibited.

A confirmation email will be sent out once we receive the contest. If you don't receive a confirmation within a day after submission, please let us know.

2025 CAC - Aurora Borealis 

Similar to last year, we will only host one CAC for students in Grade 10 and below.

Date: Friday, February 21

Time: Any time on February 21 before 8:00 PM.

Contest duration: 60 minutes

Format: Multiple-choice

The contest is administered offline. Students must reach out to one of their teachers at school to invigilate the contest. The invigilator should email info@caao.ca to indicate a student's interest. We will send out the contest to the teacher on the day of.

There is no registration fee required. Students placed in the top 3 will receive cash prizes.

First place: $50

Second place: $30

Third place: $15

The registration deadline is on February 19. Kindly let us know whether you'd like to participate before then.

CAAO 2025

The Canadian Astronomy and Astrophysics Olympiads (CAAO) 2025 are scheduled to commence on Sunday, March 9 at 12:00 PM ET (9:00 AM PT). The contest will be posted on this website at that time.

All participants are required to register for the competition. A registration fee of $15 applies. Please e-transfer the registration fee to payment@caao.ca.

Students can register by sending an email to info@caao.ca with the following information:

- First and Last Name

- Grade

- School Name, City, Province

- Date of Birth

- Citizenship Status

- Email for Contact

To prove that you’ve made the payment, take a screenshot and write in the e-transfer message: This is the CAAO payment for [student name]. Attach the payment proof in the registration email.

Students have time to register until the end of the competition, which is on Sunday, March 16, at 12:00 PM ET (9:00 AM PT).

Participants will have one week to complete the contest and submit their handwritten solutions to info@caao.ca. We would like to remind participants that typed-up solutions will NOT be accepted.

The deadline for the submission of CAAO solutions is at 12:00 PM ET (9:00 AM PT) on Sunday, March 16. We encourage all interested students to take part in this Olympiad competition and showcase their knowledge in astronomy and astrophysics. The Canadian IOAA team will be chosen from the top 5 students from the CAAO.

The top 15 students in the CAAO will have the opportunity to participate in an in-person training camp, where they will receive further training and preparation for the upcoming IOAA. This year, the IOAA will be held in Mumbai, India from August 11 to 21, 2025.

Students from any country can participate in the CAAO. However, only Canadian citizens or permanent residents will have the opportunity to represent Canada at the international Olympiads.

We wish all participants the best of luck in the CAAO.

CAAO Junior 2024

The CAAO Junior 2024 is organized and conducted by the Canadian Association of Amateur Astronomers (CAAA) in partnership with the Perimeter Institute. The CAAO Junior is the selection exam for team Canada to participate at the IOAA Junior.

The CAAO Junior is now available to download. Please read the following instructions carefully before starting.

CAAO Junior Rules and Guidelines:

Students from any grade and school in Canada can take part in this Olympiad competition. However, only Canadian citizens or permanent residents will be invited to the Canadian team.

Participants will have one week to complete the CAAO Junior. The deadline is June 2 at 11:59 PM ET (8:59 PM PT). The CAAO Junior results will be released before the end of June.

Books, online resources, and calculators are allowed.

Collaboration with others, posting on forums, or paying for external help is not allowed.

There is no registration requirement. Any interested students can download the contest and participate. To be eligible for the IOAA Junior selection, please write your solution neatly on separate pieces of paper and email back to info@caao.ca before the deadline.

Include the following information in the email when submitting your solutions:

- Student's full name (first name, last name)

- School name, city, province

- Grade

- Email

- Date of birth

A confirmation email will be sent out once we receive the contest. If you don't receive a confirmation within a day after submission, please let us know.

CAAO 2023 Winners Results

We have finalized the results for the CAAO 2023. Please check the results here.

The top 12 students for the CAAO will be invited to the three-day national camp from June 27 - 29. We will send out more details regarding the national camp in an email.

CAC 2023 Results

We want to thank all the students for participating in the first Canadian Astronomy Competition. We will distribute the prize to top participants within the next couple of weeks. The results for the top five contests in each division have been posted here.

2022 Team Canada IAO Results

Congratulations to our 2022 IRAO teams. This year, William Deng received a Silver Medal and the best result in the practical round.

Beta Group (Senior Team)

- William Deng

- Emma Yao

Alpha Group (Junior Team)

- Zhengyi (Jenny) Wu

- Olivia Kay

- Lillian Li

2022 Team Canada IOAA Results

Congratulations to our 2022 IOAA teams. This year, Team Canada achieved its best result ever.

Daniel Yang – Gold Medal (ranked 5th in the world and 1st in the data analysis section)

Connor Wong – Silver Medal

Zander Li – Silver Medal

Hongyi Huang – Bronze Medal

Simon Wu – Honourable Mention

Yuehan Hu – Specialize Prize from the Georgian National Observatory

New Partners and Sponsors

We would like to express our sincere appreciation to Perimeter Institute for their generous support. Your support is essential to help us bringing astronomy and astrophysics education to more students across Canada.

CAAO 2023

The CAAO 2023 is organized and conducted by the Canadian Association of Amateur Astronomers (CAAA) in partnership with the Perimeter Institute. The CAAO is the selection exam for team Canada to participate at the IOAA.

The CAAO is now available to download. Please read the following instructions carefully before starting.

CAAO Rules and Guidelines:

Students from any grade and school in Canada can take part in this Olympiad competition. However, only Canadian citizens or permanent residents will be invited to the Canadian team.

Participants will have two weeks to complete the CAAO. The deadline is March 28 at 11:59 PM ET (8:59 PM PT). The CAAO results will be released before the end of April.

Books, online resources, and calculators are allowed.

Collaboration with others, posting on forums, or paying for external help is not allowed.

There is no registration requirement. Any interested students can download the contest and participate. To be eligible for the IOAA selection, please write your solution neatly on separate sheets of paper and email back to info@caao.ca before the deadline.

Include the following information in the email when submitting your solutions:

- Student's full name (first name, last name)

- School name, city, province

- Grade

- Email

- Date of birth

A confirmation email will be sent out once we receive the contest. If you don't receive a confirmation within a day after submission, please let us know.

Winners and participants of CAAO will be awarded with Diplomas of I, II, III. A team of participants in the IOAA will be formed from among the winners of the CAAO.

CAAO 2023

The Canadian Astronomy and Astrophysics Olympiads (CAAO) 2023 will be held beginning on Tuesday, March 14.

Participants are not required to register for the competition. Instead, the CAAO problems will be made available on our official website. Participants will have a period of two weeks to complete their work and submit their handwritten solutions to info@caao.ca. We would like to remind participants that typed-up solutions will NOT be accepted.

The deadline for submission of the CAAO solutions is at 11:59 PM ET (8:59 PM PT) on Tuesday, March 28, 2023. We encourage all interested students to take part in this prestigious competition and showcase their knowledge in astronomy and astrophysics.

The top-performing students in the CAAO will have the opportunity to participate in an online summer camp, where they will receive further training and preparation for the upcoming IOAA. Among the participants in the summer camp, the Canadian national team will be selected to represent the country at the international competition.

This year, the IOAA will be held in Poland from the August 10 - 20. Additionally, the junior IOAA competition will be held in Greece from September 24 to 30. In order to qualify for the junior team, participants must be born after January 1, 2008.

Starting this year, only Canadian citizens or permanent residents will have the opportunity to represent Canada at the international Olympiads.

Please check out the new CAAO preparation materials below. We wish all participants best of luck at the CAAO.

Introducing the new Canadian Astronomy Competition (CAC) – Aurora Borealis

The first CAC – Aurora Borealis will be administered on Friday, February 3, 2023. Students must register for the competition by filling out a form here.

Contest Format

Multiple-choice and short answer questions.

There are two divisions of the CAC:

• Junior – for students in Grade 10 and below
• Senior – for students in Grade 11 and 12

Participants can only take one of the two versions.

Contest is written through an online test-taking software called testinvite.

Results

The CAC results will be published at the end of February on the official page of the association (https://caao.ca/).

Top contestants of CAC are awarded cash prizes.

More detailed on the competition can be found by clicking the registration button.

Preparation

Additional YouTube lectures that we suggest students watch to get a better understanding of astronomy can be found in the resources page here.

Message from Dr. Zagainova

Dear participants of the 6th CAAO,

I would like to congratulate you on the successful completion of the Olympiad. You have put a lot of effort into solving the challenging problems, and I can say with confidence that you are the smartest high school astronomers in Canada. You have touched one of the most romantic and unusual sciences - the science of "Astronomy" - the science of the past, present and future. Perhaps in the future, when you work somewhere on the Moon or on Mars, the knowledge gained in preparation for this Olympiad will be useful to you. I also hope that participation in the 6th CAAO will help you with the choice of your future profession.

Sincerely,

Dr. Vera Zagainova,

Canadian Coordinator of the International Olympiad on Astronomy and Astrophysics

Chairman of the Canadian Association of Amateur Astronomers

CAAO 2022

Important Note: The deadline for the CAAO is on April 18, 11:59 PM EST. Please send your test paper to us before then.

The CAAO is now available to download. Please read the following instructions carefully before starting.

CAAO Rules and Guidelines:

Participants will have more than two weeks to complete the exam. The deadline is April 18 at 11:59 PM EST. The CAAO results will be released on April 25.

The contest consists of two divisions. The senior division is open to all students who are in Grade 12 or under. The junior division is open only to students who are 15 (born after January 1, 2007) or younger. Although not necessary, students who are 15 or younger can attempt the senior division if they want.

Books or online resources are allowed. Calculators are also allowed.

Collaboration with others, posting on forums, or paying for external help are not allowed.

There is no registration requirement. Any interested students can download the contest and participate. To be eligible for the IOAA or IAO selection, please write your solution neatly on separate sheets of paper and email back to info@caao.ca before the deadline.

Include the following information in the email when submitting your solutions:

- Student's full name (first name, last name)

- School name, city, province

- Grade

- Email

- Date of birth (To determine IAO selection)

A confirmation email will be sent out once we receive the contest. If you don't receive a confirmation within a day after submission, please let us know.