Le James-Webb repère des indices d'étoiles monstrueuses de 7000 fois la masse du Soleil !

Le télescope James-Webb découvre des étoiles monstrueuses 7000 fois la masse du Soleil, révélant des secrets fascinants de l'univers.

Massive star in metal-poor environment often have close partner

Massive stars in metal-poor galaxies often have close partners, just like the massive stars in our metal-rich Milky Way. This is discovered by an international team of seventy astronomers, co-led by Prof. Hugues Sana of the KU Leuven Institute of Astronomy. They used the European Very Large Telescope in Chile to monitor the velocity of massive stars in the Small Magellanic Cloud. The findings are published in Nature Astronomy.

Information on Service 'Photometric and Spectral Data of Galactic Wolf-Rayet Stars (WN sequence)'

Interaction between massive star winds and the interstellar medium

Massive stars drive strong winds that impact the surrounding interstellar medium, producing parsec-scale bubbles for isolated stars and superbubbles around young clusters. These bubbles can be observed across the electromagnetic spectrum, both the wind itself and the swept up interstellar gas. Runaway massive stars produce bow shocks that strongly compresses interstellar gas, producing bright infrared, optical and radio nebulae. With the detection of non-thermal radio emission from bow shocks, particle acceleration can now also be investigated. I review research on wind bubbles and bow shocks around massive stars, highlighting recent advances in infrared, radio and X-ray observations, and progress in multidimensional simulations of these nebulae. These advances enable quantitative comparisons between theory and observations and allow to test the importance of some physical processes such as thermal conduction and Kelvin-Helmholtz instability in shaping nebulae and in constraining the energetics of stellar-wind feedback to the interstellar medium.

New theoretical model claims to solve mystery of early massive galaxies

Astrophysicists from the Hebrew University of Jerusalem published a new theoretical model that solves the mystery of the formation of early massive galaxies in the universe, in Monthly Notices of the Royal Astronomical Society. The findings naturally explain recent observations conducted using the James Webb Space Telescope (JWST), which revealed a surprising excess of massive galaxies in the universe—already in the first half billion years after the Big Bang—contrary to the commonly accepted theory.

Red Alert: Massive stars sound warning they are about to go supernova

Astronomers from Liverpool John Moores University and the University of Montpellier have devised an 'early warning' system to sound the alert when a massive star is about to end its life in a supernova explosion. The work was published in Monthly Notices of the Royal Astronomical Society.