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A new theoretical study shows that the holes in the structure observed by the James Webb Space Telescope called “Green Monster” within the Cassiopeia A (Cas A) supernova remnant is due to the interaction between a pre-existing layer of circumstellar material, impacted by the supernova shock wave, and elongated stellar fragments produced by hydrodynamic instabilities.   Supernova remnants are objects of

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To date, exoplanetary transits have allowed astronomers to discovery more than 70% of known exoplanets. Besides, by analysing stellar spectra acquired during the transits it is possible to study the atmospheres of the transiting exoplanet. During the transit, in fact, the planet is crossing the stellar disc, causing a small and periodic dimming of stellar observed flux. If the exoplanet

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Accretion is a ubiquitous phenomenon in the Universe, occurring over a wide rande of scales: From the small T Tauri stars to the enormous black holes in the center of galaxies. In particular, T Tauri stars are very young stars (a few million years old) still surrounded by a disk, called protoplanetary disk, and still acrreting gas from their disks.

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Stars more massive than 9 solar masses end their evolution in spectacular supernova explosions. These explosions are triggered by the gravitational collapse of the core of such massive stars, once the thermonuclear reactions are exhausted and the core is not supported against gravity by the pressure produced by the reactions. Supernovae are not simple spherical explosions, but rather complex phenomena

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The development of numerical models is a powerful method to explore properties and evolution of astrophysical objects, mainly for remote objects or when the necessary spatial details are higher than the resolution of modern telescopes. These models can be both hydrodynamical or magneto-hydrodynamical, depending on the importance of the effects related to the magnetic fields. In the last years, the

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