The discovery of six pre-main-sequence spectroscopic binaries

Abstract

Six premain-sequence (PMS) spectroscopic binaries were discovered in the naked T Tauri population of the Taurus-Auriga, Scorpius-Ophiuchus, and Corona Australis star-forming regions. The results imply that the short-period binary frequency of naked T Tauri stars (NTTSs) is indistinguishable from that found among population I solar-mass stars. For a short-period binary frequency of about 10 percent, the action of short-period binary components in disrupting accretion disks cannot be the dominant mechanism converting classical T Tauri stars into NTTSs. It is found that by an age of 10 to the 6th yr, short-period binary systems exist, and that among the PMS binaries discovered to date, all binaries with periods of less than 3.9 days have circular orbits and those with longer periods have eccentric orbits. 43 refs.