What's New
CAAO Jr. 2026
The Canadian Astronomy and Astrophysics Olympiads Junior (CAAO Jr.) 2026 is scheduled to commence on Saturday, May 23 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 $30 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, May 24, at 12:00 PM ET (9:00 AM PT).
Participants will have one day 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 Sunday, May 24, at 12:00 PM ET (9:00 AM PT). The Canadian IOAA Jr team will be chosen from the top 5 students from the CAAO Jr.
The top 15-20 students in the CAAO Jr will have the opportunity to participate in a training camp, where they will receive further training and preparation for the upcoming IOAA Jr. This year, the IOAA Jr will be held in Ubon Ratchathani, Thailand from November 1 - 8, 2026.
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 Senior 2026 Results
The results for the top 20 CAAO Senior 2026 participants are out. Please check the results here.
The top 25 students for the CAAO Senior will be invited to the three-day national camp. We will send out more details regarding the national camp in an email soon.
2026 Astronomy Contest Dates
Update: The CAAO Jr camp date has been posted below.
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 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.
CAAO Junior Camp
The training camp is for students who have performed well on the CAAO Junior. The IOAA Jr team will be formed based on students’ CAAO and camp exam results.
Date: June 20-21, 2026.
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.
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.
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 https://ift.tt/mSNa6DC
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 https://ift.tt/cryfIHk