di Mario Giuseppe Guarcello ( segui mguarce) Lo studio dell’emissione di raggi X dalle stelle offre molte diagnostiche di fenomeni stellari ad alta energia. Nelle stelle massive (di classe spettrale O le B più calde) raggi X “soffici” (con energia generalmente minore di 1keV, corrispondente a temperature minori di 10 milioni di gradi) sono emessi in shock nei
Stars in several star forming regions are observed with a spread in age. This support the idea that star formation is a “slow” process which can propagate across a molecular cloud over million of years (as suggested, for instance, by the Palla & Stahler 2000 study), while several authors have instead suggested that star formation is a “fast” process (e.g.
di Mario Giuseppe Guarcello ( segui mguarce) Dal 24 al 27 Settembre 2018, si terrà a Palermo, presso il Real Teatro di S. Cecilia, il meeting internazionale “Exploring the Hot and Energetic Universe”, dedicato al telescopio ai raggi X Athena (Advanced Telescope for High-Energy Astrophysics). Athena, una missione in fase di studio del programma “Cosmic Vision” di ESA
di Mario Giuseppe Guarcello ( segui mguarce) Il 5 Febbraio 2018, in occasione dell’apertura a Roma, presso il Ministero degli affari esteri, della riunione annuale degli addetti scientifici e addetti spaziali, il ministro degli Esteri Angelino Alfano ha consegnato alla ricercatrice palermitana Eleonora Troja il Premio Farnesina, come riconoscimento per la prima osservazione di un segnale ai raggi
di Mario Giuseppe Guarcello ( segui mguarce) Il Solar Dynamics Observatory (SDO) ha osservato sul Sole in più di un’occasione frammenti di plasma espulsi dopo eventi eruttivi nella corona solare che ricadono sul Sole seguendo traiettorie che deviano da quella parabolica a causa dell’interazione tra plasma e campo magnetico locale. Queste osservazioni sono da tempo oggetto di studio
The study of star-forming regions of our Galaxy is one of the main research topic of the Astronomical Observatory of Palermo. This because they can provide crucial information on how large molecular clouds collapse and form stars, on the early stellar evolutionary stages, on the formation of planetary systems, the formation and dispersion of protoplanetary disks, and the history and
The study of binary systems plays an important role in several fields of astronomy such as stellar evolution and galactic archeology since it allows direct measurements of stellar parameters such as masses, radii, and luminosities. Multiple stellar systems have typically small angular separation and thus they are not resolved by direct imaging. In these cases spectroscopy is a powerful tool
The analysis of radial velocity is one of the two main methods used to detect exoplanets. This method consists in measuring the Doppler effect on stellar spectra deriving the velocity component along the line of sight (the radial velocity). If the star has a planet, they both orbit around the common center of mass, producing periodic oscillations of the osberved
The Orion Molecular Cloud is likely the best target for studying star formation. In the past few million years, in fact, this cloud formed thousands stars over a wide range of stellar masses and in several episodes with different characteristics: From isolated low mass stars to populated and massive stellar clusters; from star formation from self-collapsing clouds to triggered star
“Stars form from the gravitational contraction of molecular clouds”: This is the basic concept of star formation process. However, the reality is much more complicated than this. The process that cause large (typically tens of light years) and cold (few degrees K) clouds of gas and dust to collapse into stars consists in a complex interplay between gravity, gas turbulence,
