- The research team led by Professor Lee Jeong-eun of Seoul National University published their findings in Nature.
- Their study provides a new milestone in understanding the mechanisms of planet formation.
The Ministry of Science and ICT (MSIT, Deputy Prime Minister and Minister: Bae Kyung-hoon) announced that a research team led by Lee Jeong-eun, a professor at Seoul National University, has observed and demonstrated for the first time in the world how silicates crystallize during star formation.
The research*, supported by MSIT through its basic research projects for individual researchers and research labs, was published in Nature, one of the world’s most prestigious scientific journals, on January 22 (Wednesday, January 21, 16:00 GMT).
* Title: Accretion bursts crystallize silicates in a planet-forming disk
Silicates, which account for about 90 percent of the Earth’s crust, are key components of terrestrial planets and comets.
Crystalline silicates are minerals known to form only at very high temperatures above 600 degrees Celsius. However, these silicates have been discovered in comets located in the extremely cold outer regions of the solar system. This has long raised questions of how minerals formed at such high temperatures could have reached the outer regions of the solar system.
While various theories, such as turbulent mixing and large-scale particle transport, had been proposed by researchers around the world, there had been no direct observational evidence showing how silicates crystallize and are transported simultaneously.
Professor Lee, who has studied star formation for over 20 years, hypothesized that the explosive mass accretion of protostars could fundamentally change the chemical state of the minerals that make up comets. At the time, however, no telescope possessed the sensitivity and resolution necessary to accurately observe such changes.
This changed with the successful launch of NASA’s James Webb Space Telescope (JWST), which provided the high-performance capabilities required to test these theoretical predictions. With this breakthrough, Professor Lee was finally able to conduct the research she had long envisioned.
The team, the only research group in Korea to secure observation time on JWST, focused on the protostar EC 53, which is located in the Serpens Nebula*. EC 53’s brightness varies roughly every 18 months, allowing researchers to clearly distinguish between its calm and outburst phases.
* Serpens Nebula: A star-forming region composed of hydrogen and dust, located in the constellation Serpens.
By observing both the calm and outburst phases, the team found that emission features from crystalline silicates were detected only during the outburst phase. This confirmed that silicate crystallization actually occurs in the hot inner region of the disk close to the protostar. The team also demonstrated that the newly formed crystalline silicates can be transported outward to the cold outer regions by disk winds.
The team’s long-refined theoretical predictions have finally been confirmed through observation, making the world’s first discovery of the mechanisms underlying the formation and transport of crystalline silicates.
“This discovery shows how years of accumulated experience can lead to scientific breakthroughs,” said Professor Lee. “We plan to continue follow-up observations to verify the universality of silicate crystallization and transport, as well as to examine how these processes are influenced by different stages of stellar evolution.”
For further information, please contact the Public Relations Division (Phone: +82-44-202-4034, E-mail: msitmedia@korea.kr) of the Ministry of Science and ICT.
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