Superfast fragments and X-ray emission in the supernova remnant SN 1006. The study: “Indication of a fast ejecta fragment in the atomic cloud interacting with the southwestern limb of SN 1006” of R. Giuffrida (UNIPA/INAF) appeared on A&A

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,

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A study on the coronal activity in a complete sample of M stars nearby to the Sun. The paper: “Complete X-ray census of M dwarfs in the solar neighborhood. I. GJ 745 AB: Coronal-hole stars in the 10 pc sample” of M. Caramazza (Eberhard-Karls Universität Tübingen) appeared on A&A

The corona is the outermost part of the atmosphere of the vast majority of stars, where the plasma is heated to millions of degrees by stellar magnetic activity. Since both the intensity and the topology of the stellar magnetic fields depend on the internal structure of stars, the study of coronal activity allows astronomers to better understand both the high-energy

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A superflare observed in the M star AD Leo. The study: “The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations” of B. Stelzer (Eberhard-Karls-Universität Tübingen) appeared on A&A

Flares are transient and energetic phenomena that occur in most stars and can be observed with high spatial and temporal resolution in the Sun. These phenomena are triggered by a sudden release of energy previously stored in the star’s magnetic field, which, after a sequence of events, leads to extreme heating of the stellar plasma. The heated plasma then rapidly

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Different regimes of particle acceleration in supernova remnants. The study: “A Spatially Resolved Study of Hard X-Ray Emission in Kepler’s Supernova Remnant: Indications of Different Regimes of Particle Acceleration” of V. Sapienza (UNIPA/OAPA) appeared on ApJ

Cosmic rays are high-energy charged particles which continuously hit our planet. These particles are accelerated up to such high velocities in different astronomical environments, among which supernova remnants seems to be particularly important. These objects are nebulae in rapid expansion generated by the explosions of very massive stars. In supernova remnants, particle acceleration seems to occurr along the expanding shock

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Supernova remnants as particle accelerators. The study: “The supernova remnant SN 1006 as a Galactic particle accelerator” of R. Giuffrida (UniPA/INAF-OAPA) recently appeared on Nature Communication

Our planet is constantly bombarded by energetic particles (mainly protons) called “cosmic rays“. The study of cosmic rays is a leading science topic given its importance in several fields, such as the study of the effects on instrumentation and astronauts in space, where the natural protection against these particles provided by the magnetic field of Earth is low or null.

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The interaction between star and planet triggers more energetic flares. The study: “X-ray variability of HD 189733 across eight years of XMM-Newton observations” of I. Pillitteri (INAF – OAPA) recently appeared on A&A

The corona is the outermost part of the atmosphere in stars with intermediate and low mass. In this region, which is extended for several stellar radii, the plasma can reach temperatures of several million degrees, emitting mainly X-ray radiation. The coronal temperature varies over a range of several orders of magnitude as a function of several stellar parameters, such as

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Photoevaporation in young planets. The study: “New Constraints on the Future Evaporation of the Young Exoplanets in the V1298 Tau System” of A. Maggio (INAF – OAPA) recently appeared on ApJ

The search for young exoplanets is crucial to our understanding of the planetary formation process and the early evolution of planets. The disc of gas and dust from which planets form, in fact, typically disperse in a few million of years. Before that, the young planets interact with all the material orbiting around the star within the disk, triggering important

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Cepheids and X-ray emission. The study “X-rays in Cepheids: XMM-Newton Observations of η Aql” of N. R. Evans (SAO-CfA) recently appeared on AJ

Cepheids are stars of great importance, since they allow to determine the distance of galaxies within a few hundreds of million of light years from us. This is due to the pulsations that characterize these giant stars, which are going through an instable phase of their evolution. Because of these pulsations, the luminosity of these stars varies with a period

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Jets launched during supernova explosions. The study: “X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals” of V. Sapienza (UNIPA/OAPA) recently appeared on A&A

Supernova remnants are clouds in rapid expansion formed by supernova explosions. Typically, these remnants are very inhomogeneous. These inhomogeneity is the result of the interaction between the expanding remnant and the surrounding material, and, in particular when they are generated by core-collapse supernova explosions (which are the supernova triggered by the gravitational collapse of the cores of massive stars), also to anisotropies formed

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A hidden companion for the cepheid V473 Lyr. The study “X-Ray Observations of the Peculiar Cepheid V473 Lyr Identify A Low-mass Companion” of N. R. Evans (Smithsonian Astrophysical Observatory) recently appeared on AJ AJ

Cepheids are pulsating giant stars, whose luminosity varies periodically. This is an important class of stars for several reasons. For instance, the period of their pulsations is related to their intrinsic luminosity. This makes cepheids a class of astronomical “standard candles”, e.g. sources whose intrinsic luminosity can be estimated, allowing us to estimate their distances by comparing intrinsic and observed

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