2025-12-18 カリフォルニア大学バークレー校
An artist’s rendition of a collision between two planetesimals in the debris disk around a young star. Collisions like these occur over hundreds of millions of years as gas and dust slowly coalesces into planets and moons.Thomas Müller (MPIA/HdA)
＜関連情報＞
- https://news.berkeley.edu/2025/12/18/astronomers-see-fireworks-from-violent-collisions-around-nearby-star/
- https://www.science.org/doi/10.1126/science.adu6266
フォーマルハウト系における2度目の微惑星衝突 A second planetesimal collision in the Fomalhaut system
Paul Kalas, Jason J. Wang, Maxwell A. Millar-Blanchaer, Bin B. Ren, […] , and Michael Fitzgerald
Science Published:18 Dec 2025
DOI:https://doi.org/10.1126/science.adu6266
Abstract
The nearby star Fomalhaut is orbited by a compact source, Fomalhaut b, which has previously been interpreted as either a dust-enshrouded exoplanet or a dust cloud generated by the collision of two planetesimals. Such collisions are rarely observed but their debris can appear in direct imaging. We report Hubble Space Telescope observations that show the appearance in 2023 of a second point source around Fomalhaut, resembling the appearance of Fomalhaut b twenty years earlier. We interpret this additional source as a dust cloud produced by a recent impact between two planetesimals. The positions and motion of two impact-generated dust clouds over twenty years provide constraints on the collisional dynamics in the debris belt.
