Category: Ricerca

A white dwarf with a peculiar variability. The study: “Discovery of a magnetic white dwarf with unusual short-period variability” of A. Scholz (University of St. Andrews) published by RNAAS

Ricerca

The study of the variability of stars and compact objects is a powerful diagnostic to unveil their physical properties. For instance, it is typical not feasible to observe directly the presence of magnetic active regions on stellar surface, pulsations, very faint companions, or close circumstellar material. These properties, however, can be studied by the variability of the observed photometry or

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Stellar activity suppressed by close-in exoplanets. The study “Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 System” of L. Fossati (Space Research Institute – Austria) published by AJ

Ricerca

All the magnetic phenomena occurring in stars, such as flares and spots, are called “stellar activity”. Astronomers study stellar activity using different diagnostics such as X-ray emission from the coronae and spectroscopic indices like the R’HK measuring the chromospheric activity. This is an important research field in stellar astronomy, given that stellar activity is connected to the intensity and morphology

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Osservata per la prima volta emissione ai raggi X associata ad una regione attiva in una stella B. Pubblicato su A&A lo studio: “Detection of magnetic field in the B2 star ρ Ophiuchi A with ESO FORS2” di I. Pillitteri (INAF-OAPA)

Ricerca

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

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Star formation history in Canis Major. Recently published by A&A “Star formation history of Canis Major OB1” of T. Santos-Silva

Ricerca

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.

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Palermo ospiterà il meeting “Exploring the Hot and Energetic Universe”

Ricerca

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

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L’astrofisica palermitana Eleonora Troja ha ricevuto il premio Farnesina

Ricerca

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

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Plasma in caduta in canali magnetici solari: pubblicato su A&A lo studio: “Guided flows in coronal magnetic flux tubes” di A. Petralia

Ricerca

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

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Two large projects (GES and CSI-2264) join forces: The study “The Gaia-ESO Survey and CSI 2264: Substructures, disks, and sequential star formation in the young open cluster NGC 2264” of L. Venuti (INAF-OAPA) recently published by A&A

Ricerca

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

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A search for binary systems with GES. The study “The Gaia-ESO Survey: double, triple, and quadruple-line spectroscopic binary candidates” by T. Merle recently appeared on A&A

Ricerca

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

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A new super-Earth discovered thanks to Harps-N. The study “HADES RV Programme with HARPS-N at TNG. GJ 3942 b behind dominant activity signals” of M. Perger published by A&A

Ricerca

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

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