 Astronomers have long sought evidence to explain why comets at the outskirts of our own solar system contain crystalline silicates, since crystals require intense heat to form and these “dirty snowballs” spend most of their time in the ultracold Kuiper Belt and Oort Cloud. Now, looking outside our solar system, NASA’s James Webb Space Telescope has returned the first conclusive evidence that links how those conditions are possible. An international team, including Prof. Gregory Herczeg at KIAA, clearly showed for the first time that the hot, inner part of the disk of gas and dust surrounding a very young, actively forming star is where crystalline silicates are forged. Webb also revealed a strong outflow that is capable of carrying the crystals to the outer edges of this disk. Compared to our own fully formed, mostly dust-cleared solar system, the crystals would be forming approximately between the Sun and Earth.
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 A research team led by Prof. Lijing Shao in the Kavli Institute for Astronomy and Astrophysics at Peking University has proposed a new Bayesian framework for gravitational-wave ringdown analysis and developed an open-source algorithm, FIREFLY, to apply to real gravitational-wave data. Since their first discovery about ten years ago, gravitational waves have become instrumental in understanding astrophysical processes, fundamental laws of physics, as well as black-hole spacetimes. Above all, useful information is eventually extracted from (usually rather noisy) data with dedicated statistical techniques.
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 Beijing, China — An international research team led by Prof. Fangzhou Jiang at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University has unveiled a new theory explaining one of the biggest astrophysical mysteries revealed by the James Webb Space Telescope, the origin of the enigmatic “Little Red Dots”. These tiny but extraordinarily bright objects at cosmic dawn appear to host supermassive black holes far larger than their surrounding galaxies should allow. Until now, their existence has posed a severe challenge to standard models of galaxy and black-hole formation and coevolution.
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 Observatories on the ground and in space captured a microlensing event when a cosmic body passed in front of a star, bending and magnifying the star’s light. Through these observations, researchers used parallax—the same phenomenon behind human depth perception, based on the spacing of our eyes—to calculate the cosmic body’s mass and distance. The method revealed the body to be a Saturn-class planet about 10,000 light years from Earth, and the first rogue planet to have its mass measured.
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 A team led by Professor Linhua Jiang and PhD student Danyang Jiang at the Kavli Institute for Astronomy and Astrophysics and School of Physics at Peking University used the James Webb Space Telescope (JWST) to conclusively rule out the possibility of AGNs being the dominant ionizing sources during the peak period of reionization, a transformative epoch in the history of our universe. Star-forming galaxies must have provided the primary ionizing photons for cosmic reionization The study, titled “AGNs ruled out as the dominant source of cosmic reionization,” was published online on October 7, 2025, in Nature Astronomy.
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 Quasars are among the brightest beacons in the Universe, powered by supermassive black holes that swallow gas at their centers. Although they shine across billions of light-years, their extreme distances and tiny sizes make it very difficult to see what is happening in the immediate surroundings of the black hole itself. Now, for the first time, an international team of astronomers, including at PKU, have managed to directly resolve the inner structure of a quasar at redshift 4—when the Universe was less than 1.5 billion years old—opening a new window into how black holes grew in the early cosmos.
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