Nam Hyun-woo has worked as a staff writer at The Korea Times since 2013, mostly covering business and politics. He currently belongs to the Business Desk where he covers topics such as emerging tech, AI, ICT and Korea's chaebol community. Prior to joining the team, he was the paper's correspondent for the presidential office of Korea during the Yoon Suk Yeol and Moon Jae-in administrations.
SNU team observes how silicates crystallize during planet formation for 1st time
Seoul National University professor Lee Jeong-eun, front row right, poses with her research team in this undated handout photo. Courtesy of Ministry of Science and ICT
By Nam Hyun-woo
A team led by Seoul National University professor Lee Jeong-eun has, for the first time, directly observed how silicates crystallize during planet formation, providing observational proof of long-standing theories about the birth of planets and comets.
According to the Ministry of Science and ICT, which supported the project, the research was published Thursday in Nature, one of the world’s most prestigious scientific journals, under the title “Accretion bursts crystallize silicates in a planet-forming disk.”
Silicates account for about 90 percent of Earth’s crust and are a key component of terrestrial planets and comets. The study addresses a long-standing mystery of how silicates — which crystallize only at temperatures above 600 degrees Celsius — can be found in comets that formed in the extremely cold outer regions of the solar system.
While various theories have been proposed, there had been no direct observational evidence showing when and where silicates crystallize and how they are transported.
Presentation material of Seoul National University professor Lee Jeong-eun's research on accretion bursts crystallizing silicates in a planet-forming disk / Courtesy of Ministry of Science and ICT
The team, the only research group in Korea to secure observation time on the James Webb Space Telescope, used it to observe the protostar EC 53, a very young star located in the Serpens Nebula. The object is known to brighten dramatically roughly every 18 months, enabling researchers to clearly distinguish between its calm and outburst phases.
By comparing the two phases, the team found that new silicate emission features appeared only during the outburst phase, called accretion burst, showing that silicate crystallization actually occurs in the hot inner region of the disk close to the protostar. The team also revealed that the newly formed crystalline silicates can be carried outward to the cold outer regions by disk winds.
Lee said the team was able to precisely observe the same protostar in both its calm and outburst phases, allowing them to track what happened before and after a single event, unlike previous studies that compared different objects or unrelated observations. She said this was made possible by the James Webb Space Telescope’s unprecedented sensitivity and spatial and spectral resolution.
“This discovery shows how long-term experience can lead to scientific breakthroughs,” Lee said. “We plan to continue follow-up observations to test how universal silicate crystallization and material transport are, and how they depend on different stages of stellar evolution.”