Melo, Claudio Henrique

Contact Email: Claudio.Melo@obs.unige.ch
Institute: Geneva Observatory
Presenting Thesis: Yes
Subject Area: Star Formation, Very Young Stars, T-Tauri, H-H Objects
Waveband: Optical
Technique: Spectroscopy
Presentation: Poster Display
Title: The short period multiplicity among the T-Tauri stars
Abstract: We present in this paper the results of high-resolution spectroscopic observations carried out during three years aiming to estimate the short-period ( P_orb<100 days) binary frequency of a sample of T-Tauri stars in Oph-Sco, Cha, Lup, CrA star forming regions (SFRs) already observed with high angular resolution techniques by Ghez et al. (1993) and by Ghez et al. (1997) to detect more wider components. When combining all four SFRs, the short-period binary frequency is indistinguishable of that found by Duquennoy & Mayor (1991) for the solar-type field stars which is also consistent with the previous result obtained by Mathieu (1992, 1994). When Oph-Sco is analyzed separately, it seems that there is an excess of short-period binaries of a factor 2-2.5, on the opposite, short-period binary systems seem to be absent in the sample containing stars in Cha/Lup/CrA. Such a trend was equally found by Mathieu (1992). However, the small size of the sample avoid drawing any robust conclusion about a possible excess (lack) of short-period binaries in Oph (Cha/Lup/CrA).