THE DARWIN TARGET LIST: OBSERVATIONAL PROPERTIES OF THE G-TYPE STARS

摘要

DARWIN is aimed to search for terrestrial extra-solar planets and to detect biosignatures in the planet atmospheres, which will largely be influenced by the parent stars. This contribution presents a first approach to the knowledge of the observational properties of the DARWIN star candidates of G spectral type: variability, X-Ray emission, stellar or planetary companions, photometric properties in the Johnson and Stromgren systems, metallicity, IR emission and rotational velocities. The information has been retrieved from different databases and catalogues. We find that some of the nearby Sun-like targets present activity in the form of variability or X-Ray emission. Few of them show far-IR excesses suggesting dusty debris disks around the stars. Further, the metallicity and rotational velocity distributions agree well with the expectations for 'normal' Sun-like stars, with the exception of few stars. This kind of work - which will be refined and extended to other spectral types in the near future - and similar ones, in addition to the expected observational and theoretical progress in the exoplanetary field, will help to ellaborate more sophisticated criteria in order to optimize the final DARWIN target list. In addition, this activity provides useful information for the GENIE scientific goal of detecting and studying exo-zodiacal light.