South Korean team takes five golds at astronomy olympiad

All five members of South Korea's delegation won gold medals at the 19th International Olympiad on Astronomy and Astrophysics, the first clean sweep of golds since the country began entering the competition, the science ministry said Tuesday.

The contest drew 312 participants from 64 countries. The gold medalists were Kim Geon-ho and Kim Hyeong-geon of Seoul Science High School, Park Ha-yun of Daejeon Science High School, Yeo Eun-su of Sejong Academy of Science and Arts, and Yoon Ye-jun of Gwangju Science High School. The delegation was led by Lee Hee-won of the Korea Astronomy Olympiad Committee, with Kim Kyung-hee of the Korean Astronomical Society as deputy and Hwang Jung-hyun of Seoul National University as mentor.

The theory paper covered astrophysics fundamentals, time and coordinates, planetary and stellar systems, the interstellar medium, cosmology and observational instruments, and posed 12 problems including the spiral structure of stellar winds from evolved stars and ultraluminous galaxies in the early universe.

The data analysis round set three problems drawn from recent James Webb Space Telescope observations, on the nature of little red dots and on verifying the equation of state of neutron stars. In the observation round, students used reflecting telescopes at night to observe Saturn and the open cluster M29 in Cygnus, calculated hour angles and applied reverberation mapping to estimate the mass of a black hole at the center of an active galactic nucleus. The planetarium round was held inside a 16-meter dome at the University of Phenikka, where students located the sun in a simulated sky viewed from the far side of the moon.

"The International Olympiad on Astronomy and Astrophysics is an important international competition where astronomy talents representing each country exchange ideas and demonstrate creative knowledge and passion for space," Lee said. "I hope our delegation students have had an opportunity to grow into valuable talent for South Korea leading the space era through their participation."

South Korean teams have performed well across eight international olympiads this year, including mathematics and physics. Only the International Junior Science Olympiad, scheduled for Dec. 2 to 9, remains.