Eventi & Seminari

Questo seminario presenterà al personale le iniziative previste nel nuovo Piano Triennale delle Azioni Positive (PTAP), proposto dal CUG e fatto proprio da INAF.
Sarà l'occasione anche per una serie di semplici riflessioni più generali attinenti ai temi propri del CUG, il Comitato Unico di Garanzia per le pari opportunità, la valorizzazione del benessere di chi lavora e contro le discriminazioni.

Supernova remnants (SNRs) result from the stellar mass ejected during a supernova explosion, and their spatial and  temporal evolution is strongly related to the interaction between the SNR shocks and the surrounding interstellar medium (ISM).
Thanks to its large size, its location well out of the Galactic plane, and its high brightness, the middle-age SNR Cygnus Loop  is well suited for observations across the entire electromagnetic spectrum. In the radio band, this SNR presents a very characteristic  morphology with a large northern circular shell and a bubble-like shell located in the southern part.
The radio studies showed substantial differences between these two regions, which could be related to the local magnetic field conditions, particle populations with different energy distribution or peculiar emission mechanisms. Despite this scientific interest, sensitive flux density measurements are missing at higher frequencies (above ∼ 5 GHz), due to the technical difficulties in performing radio continuum observations of such a large source.  These arguments made Cygnus Loop a very interesting target to observe with the Italian radio telescopes.

Most of the planets known today orbit around late-type main-sequence stars and are very close to their hosts (orbit semimajor axis < 0.2 astronomical units). Therefore, they strongly interact with them through gravitational tides, radiation, and magnetic fields as well as through the stellar winds and coronal mass ejections. Stellar magnetic fields control the high-energy radiation that is responsible for the evaporation of the atmospheres of close-by planets and that may produce the radius dichotomy observed in planets with radii smaller than 3.5-4.0 Earth radii. Moreover, stellar magnetic fields produce winds that lead to a steady loss of angular momentum from the systems braking stellar rotation and modifying the tidal evolution of planetary orbits. Finally, stellar magnetic fields may directly interact with planetary fields leading to observable effects in the stellar atmospheres in the optical and/or in the radio spectral domains. I shall briefly introduce such interactions focusing on some recent investigations that could provide information on planetary magnetic fields, in particular on those of close-by giant planets, the so-called hot Jupiters.