The New CAAO

What's New

CAAO 2023 Problem 7 Correction


It has come to our attention that Problem 7 on the competition lacks certain conditions to be able to fully solve the problem. The download button below has been updated to the newer version of the contest. The corrections are highlighted in red text.


We understand that this correction is found late into the competition, so we will keep that in mind during the grading.


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 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 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.

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.

Spiral Galaxy NGC 2841

A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This deep view of the gorgeous island universe was captured during 32 clear nights in November, December 2021 and January 2022. It shows off a striking yellow nucleus, galactic disk, and faint outer regions. Dust lanes, small star-forming regions, and young star clusters are embedded in the patchy, tightly wound spiral arms. In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way. X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841. via NASA

Dueling Bands of the Night

What are these two bands in the sky? The more commonly seen band is the one on the right and is the central band of our Milky Way galaxy. Our Sun orbits in the disk of this spiral galaxy, so that from inside, this disk appears as a band of comparable brightness all the way around the sky. The Milky Way band can also be seen all year -- if out away from city lights. The less commonly seem band, on the left, is zodiacal light -- sunlight reflected from dust orbiting the Sun in our Solar System. Zodiacal light is brightest near the Sun and so is best seen just before sunrise or just after sunset. On some evenings in the north, particularly during the months of March and April, this ribbon of zodiacal light can appear quite prominent after sunset. It was determined only this century that zodiacal dust was mostly expelled by comets that have passed near Jupiter. Only on certain times of the year will the two bands be seen side by side, in parts of the sky, like this. The featured image, including the Andromeda galaxy and a meteor, was captured in late January over a frozen lake in Kanding, Sichuan, China. via NASA