Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.arcetri.astro.it/~sait07/stelle.pdf Äàòà èçìåíåíèÿ: Mon May 14 14:34:10 2007 Äàòà èíäåêñèðîâàíèÿ: Mon Oct 1 23:31:55 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï

TALKS ST EL L E
Raffaele Gratton INAF - Osservatorio Astronomico di Padova Stellar abundances and the chemical evolution of stellar systems: the Italian contribution The chemical composition of stellar syst the last few years, exciting results have and efficient spectrographs. Italians are I will review some of the most important ems is crucial in understanding evolution of galaxies. In been obtained, thanks to availability of large telescopes at forefront in this field. results in this area.

Sergio Messina INAF - Osservatorio Astrofisico di Catania The RACE-OC project: Rotation and Activity Evolution in Open Clusters W e present an ongoing project consisting of multiband long-term CCD photometric observations of open stellar clusters of different age, ranging from about 1 to 500 Myr. Our sample consists of twelve clusters, seven of which have already been observed at least in one season. From this project we expect: a) to identify the cluster members, b) to determine the rotation period of the late-type cluster members; c) to determine their rotational period distribution; and c) to study the short-term (rotational) and long-term (cyclical) magnetic variability by using photospheric activity tracers. Once the observations of all clusters will be completed for at least one season, we plan to better describe and model the evolution of the stellar angular momentum from the PMS to the TAMS. Moreover, we intend to investigate in a statistically complete stellar sample the dependence and evolution of magnetic activity on the global stellar parameters in the framework of the current dynamo theories, thanks to the repeated year-to-year observations.

Rosario Pizzone INFN / LNS - Catania R.G. Pizzone, L. Lamia, C. Spitaleri, A. Szanto de Toledo, N. Carlin, S. Cherubini, V. CrucillÞ, M. Gameiro Munhoz, M. Gimenez del Santo, M. Gulino, M. La Cognata, S.M.R. Puglia, G.G. Rapisarda, S. Romano, M.L. Sergi, S. Tudisco, A. Tumino, R.A. ZappalÞ Light elements depletion in stellar atmospheres: the boron case In order to study the impact of the nuclear uncertainties on the light elements depletion problem in stellar atmospheres and in particular on the anomalous behaviour of the boron abundance [1], we have studied the 11B(p; a)8Be and 10B(p; a)7Be reactions. The Trojan Horse Method which allows to extract the two-body cross section from an appropriate three-body one and to avoid the difficulties related to extrapolations and electron screening effects [2,3], was applied.


In particular the 11B(p; a)8Be and 10B(p; a)7Be were studied by means of the 2H(10B; a7Be)n and 2H(11B; a8Be)n reactions, both studied at 27 MeV. In both cases the bare nucleus S(E)-factor has been measured [2] at energies corresponding to the Gamow peak. The 2H(10B; a7Be)n experiment was carried on at the Pelletron-Linac laboratory in Sao Paulo (Brazil) while the experiment 2H(11B; a8Be)n was performed at LNS Catania. The obtained results will be discussed for both reactions and they will be compared with direct data available in literature (e.g. from the NACRE compilation). In both cases information will be retrieved at energies as low as the astrophysical ones and hints on the electron screening effect will be shown.

Ennio Poretti INAF - Osservatorio Astronomico di Brera Il satellite COROT tre mesi dopo il lancio: asterosismologia e transiti planetari COROT (COnvection, ROtation and planetary Transits) Õ stato lanciato con successo il 27 dicembre 2006. Mediante misure fotometriche ad alta precisione cercherÞ di raggiungere tre obiettivi scientifici molto particolari in regioni di cielo ben definite: 1) la caratterizzazione della struttura e della dinamica degli interni stellari mediante l'asterosismologia, sia di stelle di sequenza che di giganti; 2) la scoperta di pianeti di dimensioni terrestri mediante il metodo dei transiti; 3) l'osservazione continua dallo spazio di fenomeni legati alla variabilitÞ stellare finora studiati solo da Terra. Sono anche previste osservazioni complementari da Terra, specialmente spettroscopiche ad alta risoluzione.

Salvatore Sciortino INAF - Osservatorio Astronomico di Palermo Osservazioni multibanda di ammassi aperti ed associazioni stellari giovani: recenti risultati della comunitÞ italiana Diversi gruppi italiani sono da anni coinvolti in programmi di osservazioni multibanda di ammassi aperti e associazioni stellari giovani che utilizzano sia dati da telescopi al suolo che da telescopi spaziali. Questi programmi mirano a rispondere a importanti questioni astrofisiche quali: a) la forma della IMF, la sua universalitÞ, la sua dipendenza nel tempo e dal luogo nella Galassia, etc., b) la presenza di una reale dispersione d'etÞ suggerita dalla dispersione di luminositÞ nei diagrammi HR e la sua implicazione sui processi di formazione stellare, c) l'evoluzione delle proprietÞ di stelle e dischi circumstellari dalla PMS alla ZAMS. Si illustreranno alcuni dei recenti contributi della comunitÞ italiana in questa area di ricerca

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