Monaco, L.L.MonacoSaviane, I.I.SavianePERINA, SIBILLASIBILLAPERINABELLAZZINI, MicheleMicheleBELLAZZINIBUZZONI, AlbertoAlbertoBUZZONIFederici, L.L.FedericiFusi Pecci, F.F.Fusi PecciGALLETI, SILVIASILVIAGALLETI2024-01-292024-01-2920090004-6361http://hdl.handle.net/20.500.12386/34647Context: NGC 205 is a peculiar dwarf elliptical galaxy hosting in its center a population of young blue stars. Their origin is still matter of debate, the central fresh star formation activity possibly being related to dynamical interactions between NGC 205 and M 31. <BR />Aims: The star formation history in the central 30´´ (~120 pc) around the NGC 205 central nucleus is investigated in order to obtain clues to the origin of the young stellar population. <BR />Methods: Deep HST/ACS CCD photometry is compared with theoretical isochrones and luminosity functions to characterize the stellar content of the region under study and compute the recent SF rate. <BR />Results: Our photometry reveals a previously undetected blue plume of young stars clearly distinguishable down to I≃ 26. Our analysis suggests that 1.9 × 10<SUP>5</SUP> M_⊙ were produced between approximately 62 Myr and 335 Myr ago in the NGC 205 inner regions, with a latest minor episode occurring ~25 Myr ago. This implies a star formation rate of ~7× 10<SUP>-4</SUP> M_⊙/yr over this period. <BR />Conclusions: The excellent fit of the observed luminosity function of young main sequence stars obtained with a model having a constant star formation rate argues against a tidally triggered star formation activity over the last ~300 Myr. Rather, a constant SF may be consistent with NGC 205 being on its first interaction with M 31.STAMPAenArticle10.1051/0004-6361/2009124122-s2.0-68949187657http://arxiv.org/abs/0907.0029v1https://www.aanda.org/articles/aa/full_html/2009/29/aa12412-09/aa12412-09.html2009A&A...502L...9MFIS/05 - ASTRONOMIA E ASTROFISICA