Measured the amount of plasma between 10000 and 30 million degrees—responsible for the emission of extreme UV radiation and soft X-rays—in a sample of Sun-like and low-mass stars. Sun-like stars (spectral classes FGK) and low-mass stars (spectral class M) host in their outer atmospheres (the corona) plasma at temperatures of millions of degrees. Such high temperatures are reached through
In the supernova remnant Cassiopeia A, three jets rich in material synthesized in the innermost layers of the progenitor star reveal the secrets of the processes that occur in a supernova immediately after core collapse. Understanding the phenomena that follow the collapse of a massive star core is one of the most important goals of modern astrophysics. These processes
The analysis of a long X-ray observation reveals the nature of the mysterious star Wd1-9: a binary system containing a star that has recently evolved into the Wolf-Rayet phase, after expelling the outer layers of its atmosphere, which were accreted onto the companion star. Among the at least one hundred billion stars hosted by our Galaxy, there are a
The role of supernova remnants (expanding clouds produced by supernovae) in the acceleration of cosmic rays (high-energy particles present in various astrophysical environments) has been known since 1995. The discovery, made by astronomers from Kyoto University, was made possible by identifying the presence of non-thermal X-ray emission in the supernova remnant SN 1006. X-rays are a type of high-energy radiation
Massive stars live short and violent lives. Mainly during the later stages of their evolution, these stars undergo significant changes in their structure and lose a large fraction of their initial mass into the surrounding environment as stellar winds. In particular, during the Wolf-Rayet phase, which lasts only a few hundred thousand years, massive stars eject their outer layers, which
Supernova remnants, which are nebulae produced by explosion of supernovae and undergoing rapid expansion, typically serve as intense sources of high-energy radiation, particularly in the form of X-ray emissions. This radiation can be of two different types: thermal and non-thermal. Thermal radiation is emitted by dense material and is contingent upon the temperature of the emitting gas. To emit X-rays,
Stellar clusters are important targets for studying stellar evolution and, in the case of the youngest star clusters, the products of the star and planet formation processes. Our galaxy hosts a rich population of young stellar clusters, typically with masses of a few hundred solar masses. In the solar neighborhood, for instance, there are only a few young clusters with
Today in the Milky Way, star formation typically occurs in low-mass environments. Young star clusters (e.g., younger than 10 million years), in fact, typically have a mass of a few hundred solar masses. Nevertheless, our Galaxy hosts a few very massive star-forming regions that can produce tens to hundreds of thousands of stars, including some of the most massive stars
The formation of stars and planets results from the complex interplay of various factors and agents: the collapse of the cloud due to its own gravitational force, its internal turbulence and magnetic effects, the evolution of star clusters formed within, and the interactions among young stars within these clusters, as well as the influence of their radiation on the surrounding
SN1987A, located in the Large Magellanic Cloud, is an object of great importance for the study of supernovae and supernova remnants. In fact, it is the only supernova that has occurred recently and is close enough to allow us to obtain detailed observations across the entire electromagnetic spectrum. SN1987A was a core-collapse supernova, resulting from the collapse of the core
