Clues about how galaxies like our Milky Way form and evolve and why their stars show surprising chemical patterns have been revealed by a new study. The research, published today in Monthly Notices of the Royal Astronomical Society, explores the origins of a puzzling feature in the Milky Way: the presence of two distinct groups of stars with different chemical compositions, known as the "chemical bimodality".

An international team led by researchers from the Department of Earth and Planetary Sciences at The University of Hong Kong (HKU), including postdoctoral fellow Dr Tianyang LYU, Professor Man Hoi LEE (also with the Department of Physics), and Mok Sau-King Professor Guochun ZHAO, has made a significant breakthrough in understanding the tectonic evolution of terrestrial planets. Using advanced numerical models, the team systematically classified for the first time six distinct planetary tectonic regimes and identified a novel regime: the “Episodic-Squishy Lid”. The study not only provides crucial clues to the origin of Earth’s plate tectonics but also offers a robust theoretical framework for deciphering the enigmatic geological features of Venus. The findings have been published in the journal Nature Communications.

Astronomers have captured unprecedented, detailed images of two stellar explosions—known as novae—within days of their eruption. The breakthrough provides direct evidence that these explosions are more complex than previously thought, with multiple outflows of material and, in some cases, dramatic delays in the ejection process. The international study, published in Nature Astronomy, used a cutting-edge technique called interferometry at the Center for High Angular Resolution Astronomy, or CHARA, Array in California. This approach allowed scientists, including Michigan State University researcher Laura Chomiuk, to combine the light from multiple telescopes, achieving the sharp resolution needed to directly image the rapidly evolving explosions.

An international team of astronomers led by Oskar Klein Centre (OKC) researcher Joel Johansson has discovered SN 2025wny, the first spatially resolved, gravitationally lensed superluminous supernova ever observed. The discovery provides a striking confirmation of Einstein’s theory of General Relativity and a rare window into a powerful stellar explosion from the early Universe.