Category: Ricerca

Magnetic activity in M stars. The study: “The GAPS programme at TNG. XXVI. Magnetic activity in M stars: spectroscopic monitoring of AD Leonis” of C. Di Maio (UNIPA/OAPA) recently appeared on A&A

Ricerca

Stars which are not fully radiative (e.g., less massive than 8 solar masses) produce a magnetic field in their interior whose intensity and topology depends on the type of star and internal structure. The magnetic field is then drag toward the surface and here it interacts with the plasma in the photosphere, chromosphere, and corona triggering phenomena classified as “magnetic

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A super-Earth orbiting around an old M star. The study: “GJ 357 b. A super-Earth orbiting an extremely inactive host star” of Modirrousta-Galian (UNIPA/INAF-OAPA) recently appeared on A&A

Ricerca

Despite theoretical models predict a large abundance of Earth-like planets in our Galaxy, the family of the 4284 planets discovered so far (updated at 2020/9/25, credits: NASA) counts relatively a few of such a planets. This is clearly an observational bias, due to the fact that the methods used to detect planets are not sensitive to small planets. For this

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Infrared variability in pre-Main Sequence stars. The study: “Near-infrared time-series photometry in the field of Cygnus OB2 association II. Mapping the variability of candidate members” of J. Roquette (University of Exeter/ ICEx – UFMG) recently appeared on A&A

Ricerca

Pre-Main Sequence stars are young stars whose nuclei are still not hot enough to trigger the thermonuclear reactions that will produce energy for the rest of their existence. Some of these stars are called “T Tauri”, and they are surrounded by a protoplanetary disk made of gas and dust, where planetary systems may form. T Tauri stars were classified for

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Nanoflares and nanojets and the coronal heating problem. The paper: “Reconnection Nanojets in the Solar Corona” of P. Antolin (Northumbria University) appeared on Nature Astronomy

Ricerca

Solar corona is the outer atmosphere of our star. Extended for several solar radii, it is made of million degrees plasma, thus being hotter than the gas in the photosphere (about 5600 degrees). Several scientist have tried understanding the mechanism responsible for the heating of coronal plasma, but it is has been an open issue for decades. The most promising

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Neptunians and super-Earths in systems with “cold” Jupiters as test for planetary migration theories. The study: “The GAPS programme at TNG. XXIV. An eccentric Neptune-mass planet near the inner edge of the BD-11 4672 habitable zone” of D. Barbato (UniTo/OATo) and M. Pinamonti (OATo) recently appeared on A&A

Ricerca

The architecture of planetary systems is result from both the planet formation process and a complex mechanism of radial migration of planets. This has occurred also in the Solar System, whose final architecture resulted from the migration of the gaseous giants. In particular, the theories describing the formation and migration of super-Earths and Neptunian planets predict different configurations of the

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Stellar parameters and chemical abundances from GAPS. The study: “The GAPS Programme at TNG XXV. Stellar atmospheric parameters and chemical composition through GIARPS optical and near-infrared spectra” of M. Baratella (UniPd) recently appeared on A&A

Ricerca

Several astronomical studies rely on the precise determination of the chemical abundances of stars. For instance, the determination of chemical abundances of stars in different sites of the Milky Way, or with different age or evolutionary phase, can provide precious information on the evolution of our Galaxy. However, recently it has been discovered that spectroscopic determination of stellar chemical abundances

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Exoplanets with extended evaporating atmospheres. The study: “The GAPS programme at TNG. XXII: The GIARPS view of the extended helium atmosphere of HD 189733 b accounting for stellar activity” of G. Guilluy (UniTO/INAF-OATo) recently appeared on A&A

Ricerca

The number of known exoplanets discovered so far (4197 planets, updated at 2020/August/4th, from NASA) is large enough to allow us to study their global properties. One of these properties, still lacking a proper explanation, is the so-called “Neptunian desert”, e.g. the lack of intermediate planets with orbital periods shorter than 3 days. One of the hypotheses that can explain the Neptunian

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Ices and X-rays to explain chemical abundances in protoplanetary disks. The study: “X-ray processing of a realistic ice mantle can explain the gas abundances in protoplanetary disks” of A. Ciaravella (INAF-OAPA) recently appeared on PNAS

Ricerca

To understand how planets form, it is mandatory to study the evolution of protoplanetary disks, e.g. disks of gas and dust grains orbiting around stars during the first 3-5 million years of their evolution, a that may evolve into planetary systems. In the last years, several observations have been done in order to detect the molecules, mainly organic, in these

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