Tag: Maldonado

A binary system in orbital synchronization. The study: “The GAPS programme at TNG. XLIII. A massive brown dwarf orbiting the active M dwarf TOI-5375” of J. Maldonado (INAF – OAPA) appeared on A&A

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Nature sets a lower limit on stellar masses: objects less massive than 0.07-0.08 solar masses are incapable of initiating the thermonuclear reactions that power more massive stars. Below this threshold lies the realm of brown dwarfs, objects whose mass is too small to qualify as stars, yet too large to be categorized as planets.   The mechanism responsible for the

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Stellar age and magnetic activity. The study: “The GAPS programme at TNG XXXIV. Activity-rotation, flux–flux relationships, and active-region evolution through stellar age” of J. Maldonado (INAF-OAPA) recently appeared on A&A

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Almost all stars in the Universe produce their own magnetic field with a process called stellar dynamo, whose basic ingredients are stellar rotation and convection. In general, magnetic fields are produced and are affected by charged particles, which is what stellar plasma is made of. In stars the magnetic field and plasma thus interact, producing a class of transient phenomena

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There is no relation between age and metallicity of the stars in the Solar neighbourhood. The study: “Constraining the solar neighbourhood age-metallicity relation from white dwarf-main sequence binaries” of A. Rebassa-Mansergas (Universitat Politècnica de Catalunya) recently appeared on MNRAS

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After the Big Bang, the Universe contained only hydrogen, helium, and a very small fraction of lithium. After that, stars, mainly the most massive ones, were responsible for the chemical enrichment of the Universe. In fact, stars produce energy by synthetizing chemical elements in their cores. These elements are then redistributed in the interstellar medium when stars end their evolution.

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A super-Earth for the star GJ 9689. The study: “HADES RV programme with HARPS-N at TNG. XIV. A candidate super-Earth orbiting the M-dwarf GJ 9689 with a period close to half the stellar rotation period” of J. Maldonado (INAF-OAPA) recently appeared on A&A

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M stars are the most common stars in the Universe. They have a mass ranging between 0.6 and 0.08 Solar masses in the main sequence, and an effective temperature ranging between 3900 K and 2400 K. In these stars, the signals due to the presence of planets, such as radial velocity (periodic oscillations of the star from its rest position

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