Tag: UV

The XUV emission of the star HIP67522 and the evolution of its exoplanet. The study: “XUV irradiation of young planetary atmospheres. Results from a joint XMM-Newton and HST observation of HIP67522” of A. Maggio (INAF-OAPA) appeared on A&A

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Despite the wide array of telescopes and satellites available to the astronomical community, there is a type of radiation to which we are virtually blind: the extreme UV band. This is high-energy radiation with a wavelength that ranges from the Lyman-α emission, caused by hydrogen atoms whose electron transitions from the innermost orbital (the ground state) to the second (n=2),

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Two bright flares in DS Tuc A and their impact on the nearby planet. The paper: “X-ray flares of the young planet host Ds Tucanae A” of I. Pillitteri recently appeared on A&A

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Flares are among the most energetic magnetic phenomena occuring in stars. They are triggered by a sudden release of energy previously stored in the stellar magnetic field, and then they culminate with the formation of magnetic loops in the stellar coronae filled by X-ray and UV emitting plasma at million degrees. Sometimes, these magnetic structures erupt, releasing in the surrounding

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Stellar activity suppressed by close-in exoplanets. The study “Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 System” of L. Fossati (Space Research Institute – Austria) published by AJ

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All the magnetic phenomena occurring in stars, such as flares and spots, are called “stellar activity”. Astronomers study stellar activity using different diagnostics such as X-ray emission from the coronae and spectroscopic indices like the R’HK measuring the chromospheric activity. This is an important research field in stellar astronomy, given that stellar activity is connected to the intensity and morphology

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