Photometric/spectroscopic analyses and magnetic activity in young late-type stars

15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun -- JUL 21-25, 2008 -- St Andrews, SCOTLANDWOS: 000264752500121We present preliminary results of a study in progress based on photometric and spectroscopic observations of young weak-line T Tauri and post-T Tauri stars just arriving on the Zero Aye Main Sequence. The study is part of a project based on high-resolution spectra obtained with FOCES@CAHA (Spain) and SARG@TNG (Spain) and contemporaneous photometry performed at Catania (Italy) and TUBITAK (Turkey) observatories. The main aim is to investigate the topology of magic active regions at photospheric and chromospheric levels in young single stars. Since our targets arc slow rotators, with rotation periods longer than about 2 days, we are able to apply the spectroscopic technique hawed on line-depth ratio for the measure of the photospheric temperature modulation. These stars. possible members of Stellar Kinematic Groups, display emission cores to the Call H&K and IRT lines, as well as a conspicuous filling-in of the H alpha core. Moreover. we derive lithium abundance. and measure rotational and radial velocities. In several cases we detect a clear rotational modulation of brightness. In this work we briefly mention some preliminary results obtained for SAO 51891. We have also developed a spot/plage model to he applied to the data deriving the spot parameters (filling factor and temperature) and recovering information about the chromospheric inhomogeneities (flux contrast and filling factor). This study will contribute to explore the correlations between global stellar parameters anti spot/plage characteristics in;tars with different activity level and evolutionary stage.Royal Astron Soc, Scottish Univ Phys Alliance, European Space Agcy, NASA Astrobiol InstItalian Ministry dell'Istruzione, Universitate Ricerca (MIUR)We thank the OACt, TNG, CAHA, and TUG teams for the assistance during the observations. This work has been supported by the Italian Ministry dell'Istruzione, Universitate Ricerca (MIUR) which is greatfully acknowledged. This research has made use of SIMBAD and VIZIER databases, operated at CDS, Strasbourg (France)