The spectroscopic orbit of Theta2 Tauri

Peterson, Deane M.
State University of New York, Stony Brook, NY

Stevanik, R. P.; Latham, D. W.
Harvard-Smithsonian Center for Astrophysics, Cambridge, MA

We reconsider the Hyades spectroscopic binary Theta2 Tau using data taken with the Oak Ridge Observatory Echelle-Reticon system. The data are reduced with synthetic spectra templates from the latest Kurucz models. Owing to the limited spectral coverage we are unable to improve on the mass ratio determination. However, we derive the primary velocities taking full account of the presence of the secondary. The orbit derived is consistent with the earlier efforts, but is freed of possible biases from the (undetected) presence of the secondary. Using the recent interferometric measures of Theta2 Tau, we derive a distance modulus to the cluster of 44.8 +/- 1.5 pc, after correcting for the fact that the system is foreground to the cluster center by 0.12 mag. This is closer than, but in rough agreement with, recent determinations. The major uncertainty among the orbital elements remains the mass ratio.

Astronomical Journal, 1993, vol. 105, no. 6, p. 2260-2264.

[Wyeth Reflector]