The Smallest Mass Ratio Young Star Spectroscopic Binaries
نویسندگان
چکیده
Using high resolution near-infrared spectroscopy with the Keck telescope, we have detected the radial velocity signatures of the cool secondary components in four optically identified pre−main-sequence, single-lined spectroscopic binaries. All are weak-lined T Tauri stars with well-defined center of mass velocities. The mass ratio for one young binary, NTTS 160905−1859, is M2/M1 = 0.18±0.01, the smallest yet measured dynamically for a pre−main-sequence spectroscopic binary. These new results demonstrate the power of infrared spectroscopy for the dynamical identification of cool secondaries. Visible light spectroscopy, to date, has not revealed any pre−main-sequence secondary stars with masses <0.5 M⊙, while two of the young systems reported here are in that range. We compare our targets with a compilation of the published young double-lined spectroscopic binaries and discuss our unique contribution to this sample. Subject headings: binaries: spectroscopic — stars: pre−main-sequence
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