Multiplicity of T Tauri Stars in different Star-Forming Regions
Abstract
It is now a commonly accepted fact that all or nearly all T Tauri stars (TTS) in the Taurus-Auriga star-forming region form in binary systems (Leinert et al.\ 1993, A&A 278, 129; Koehler & Leinert, 1998, A&A 331, 977). Surveys in the Orion Trapezium Cluster found a frequency of binary systems similar to that of solar-type stars on the main sequence (Prosser et al., 1994, ApJ 421, 517; Petr et al., 1998, ApJ 500, 825). Our NIR-speckle survey of TTS in Scorpius-Centaurus resulted in a binary frequency enhanced by a factor of about 1.6 compared to main-sequence stars. This is between the binary frequency of low-mass stars in the Trapezium and that of TTS in Taurus-Auriga. Furthermore, we find a difference between the binaries in the two subgroups Upper Scorpius A and Upper Scorpius B. Although the binary frequencies are comparable, the distributions over the orbital periods are significantly different. This leads to the conclusion that the multiplicity of young stars is caused by some environmental effect. To test this theory, it is necessary to survey other star-forming regions to study the binary frequency and period distributions under different conditions. Therefore, we carried out a NIR-speckle survey of 80 TTS in the T association Chamaeleon, a star-forming region similar to Taurus-Auriga. The first results of this survey will be presented.
- Publication:
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Astronomische Gesellschaft Abstract Series
- Pub Date:
- 1998
- Bibcode:
- 1998AGAb...14...17K
- Keywords:
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- T Tauri Stars: Binaries