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Notte Europea dei Ricercatori 2023

In occasione della Notte Europea dei Ricercatori 2022, l’INAF-Osservatorio Astrofisico di Catania ha organizzato varie attività per il pubblico che si svolgeranno tra il 28 e il 30 settembre.

Il mese della Ciminiera Scientifica

Città della Scienza via Simeto 23, Catania, Italia

Dal 13 maggio al 12 giugno, Citta della Scienza illuminerà di scienza la città con proiezione olografiche nella grande vetrina su Viale Libertà e Videomapping della Ciminiera. Sarà un mese ricco di seminari scientifici aperti alla cittadinanza, visite guidate del museo, laboratori per i più piccoli e meno piccoli e molto altro.

Gravitational entropy proposals adaptable to structure formation in Cosmology

Sede A. Riccò Via Santa Sofia 78, Catania

I would like to summarize and present cosmological applications of two proposals of Gravitational entropy, which are distinct from the standard holographic approach and from the entropy of the sources. One is the proposal by Clifton-Ellis and Tabakol (CET) based on the Bel-Robinson tensor, the other by Hosoya and Buchert (HB), based on the Leibler-Kullbach functional of Information Theory. By applying these proposals to inhomogenous dust solutions of Einstein’s equations (LTB and Szekeres models), we have shown in various published articles that both proposals are equivalent in their predictions, but CET is local and HB is non-local. Both yield entropy production in spacetime regions that can be characterized by generation and growth of structure (either overdensities or voids). The CET proposal provides an interesting interpretation of the cosmological constant as an asymptotic gravitational temperature that characterizes a finite entropy saturation value.

Determination of fundamental stellar parameters on massive stars

Sede A. Riccò Via Santa Sofia 78, Catania

Massive stars (i.e. the progenitors of core-collapse supernovae) are quite scarce, but play a crucial role in several important astrophysical phenomena, as for example, the chemical evolution of their host galaxies. Even so, their fundamental stellar parameters (as mass, radii, temperature and luminosity) are poorly known. This relates to important uncertainties about their formation processes, structure and evolution. We are attempting to face this challenge at the research group GEMAE (Grupo de investigación en Estrellas Masivas y Agrupaciones Estelares) at the University of La Plata, together with collaborators in Chile and Spain. We rely mainly on high-quality and high-resolution spectroscopic data collected by 18 years by the OWN Survey of the O-type and WN-stars in the Southern hemisphere. In this talk I will outline the work that we are developing at GEMAE, focusing on determinations of masses of close binary stars by spectroscopy and photometry in the optic and near-infrared bands.

The evolution of young low-mass stars: focus on rotation and activity

Sede A. Riccò Via Santa Sofia 78, Catania

Between its formation stage as an active accreting seed and today, the Sun underwent large structural changes as well as variation in magnetic activity, rotation rate and its relation to the surrounding environment. I will go through the different processes that are responsible for these changes and present our latest results on the subject. We will go from the early interaction between the star and its proto-planetary disc bathing in UV radiations emitted from the massive neighbours, to the internal mixing happening in the inner layers of solar-like stars that are probed by asteroseismology.
Finally, I will review the possible applications of this work to other types of stars at different stages of the evolution in the context of the current or future surveys.

D.D.302/2023 Concorso pubblico per titoli ed esame, ai fini del reclutamento di un “Tecnologo”, Terzo Livello Professionale, con contratto di lavoro a tempo determinato e regime di impegno a tempo pieno, della durata di 18 mesi, eventualmente prorogabili, per lo svolgimento dell’attività di “Supporto attività STILES 6300 TestingWFInstrumentOnSky”

Concorso pubblico per titoli ed esame, ai fini del reclutamento di un "Tecnologo", Terzo Livello Professionale, con contratto di lavoro a tempo determinato e regime di impegno a tempo pieno, […]