Cutispoto, Giuseppe

Contact Email: gcutispoto@alpha4.ct.astro.it
Institute: Catania Astrophysical Observatory
First Coauthor: Livio Pastori
Institute: Brera Astronomical Observatory
Second Coauthor: Luca Pasquini
Institute: European Southern Observatory
Research URL:http://www.ct.astro.it/cutispoto/home.html
Subject Area: Surveys & Catalogs
Waveband: Optical
Technique: Spectroscopy
Presentation:
Title: Fast-rotating nearby solar-type stars. Spectral classification, Li abundances and X-ray luminosities
Abstract: We present the results of high-resolution spectroscopic and high-precision UBV(RI)c photometric observations obtained at the European Southern Observatory for a sample of 129 fast-rotating late-F and G-type nearby stars. Using also data from the Hipparcos, CORAVEL and ROSAT databases we infer accurate spectral types, compute vsini, Li abundances and X-ray luminosities and investigate the single or binary nature of the sample stars. We find that the selected stars show statistically higher Li abundances and activity levels than samples of field stars with similar spectral types. The analysis of our sample show also a relevant fraction of close binaries and of young single stars. In particular, at least 8 single stars can be considered bona-fide PMS or ZAMS objects and 30 stars are identified as SBs for the first time. Surprisingly, we also found at least three rapid-rotating apparently single MS stars with very low Li abundances. The results on our sample confirm the presence of young very active stars close to the Sun, in agreement with recent findings coming from UV and X-ray surveys, although our sample has not so extreme characteristics as the UV and X-ray selected ones.