AAS 203rd Meeting, January 2004
Session 5 T Tauri Stars
Poster, Monday, January 5, 2004, 9:20am-6:30pm, Grand Hall

## [5.08] Dynamical Mass of the T Tau Sa-Sb Binary

G. H. Schaefer (SUNY Stony Brook), T. L. Beck (Gemini Observatory), L. Prato (UCLA), M. Simon (SUNY Stony Brook)

It is possible to derive a useful value for the dynamical mass of a binary system even if a complete orbit has not yet been observed. By considering the distribution of masses produced by orbital solutions that lie within a variation of 1 from the minimum in the reduced \chi2 surface, an estimate of the total mass can be derived. We apply this technique to the infrared measurements of the resolved T Tau Sa-Sb binary. This pair, currently separated by ~ 0.1'' is located ~ 0.7'' south of T Tau N. Curvature is already apparent in the orbital motion of Tau Sa-Sb. Although the range of possible orbital parameters is still large, the total mass lies within the range 3.7 (+2.8/-1.6) Msun. Comparing this value to the masses of T Tau N and T Tau Sb estimated from their spectral types, indicates that the IR companion, T Tau Sa, is the most massive component.

Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.