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000002268 005__ 20160701171702.0
000002268 037__ $$aASTROimport-425
000002268 100__ $$aMartayan, C.
000002268 245__ $$aEvolution of massive Be and Oe stars at low metallicity towards the Long Gamma Ray bursts
000002268 260__ $$c2011
000002268 520__ $$astars rotate faster than in environments of high metallicity. This is a typical case in the SMC. As a consequence, it is expected that a larger number of fast rotators is found in the SMC than in the Galaxy, in particular a higher fraction of Be/Oe stars. Using the ESO-WFI in its slitless mode, the data from the SMC open clusters were examined and an occurrence of Be stars 3 to 5 times larger than in the Galaxy was found. The evolution of the angular rotational velocity at different metallicities seems to be the main key to understand the specific behavior and evolution of these stars. According to the results form the WFI study, the observational clues drawn from the WR stars and other massive stars in the SMC, and relying on the model predictions regarding the characteristics that LGRBs-progenitors should have on the ZAMS, we concluded that low metallicity Oe/Be stars are potential progenitors of LGRBs. In this document, we describe the different steps followed in these studies: determination of the number of Be/Oe stars at different metallicities, identification of the clues that lead to suppose the low metallicity Be/Oe stars as LGRB progenitors, comparison of models with observations. 
000002268 700__ $$a Zorec, J.
000002268 700__ $$a Baade, D.
000002268 700__ $$a Frémat, Y.
000002268 700__ $$a Fabregat, J.
000002268 700__ $$a Ekström, S.
000002268 773__ $$c285-290$$pBulletin de la Societe Royale des Sciences de Liege$$v80$$y2011
000002268 85642 $$ahttp://esoads.eso.org/abs/2011BSRSL..80..285M
000002268 905__ $$apublished in
000002268 980__ $$aREFERD