MASSES AND DISTANCE OF THE YOUNG BINARY NTTS 045251+3016

As part of our continuing campaign to measure the masses of pre-main-sequence (PMS) stars dynamically and thus to assess the reliability of the discrepant theoretical calculations of contraction to the main sequence, we present new results for NTTS 045251+3016, a visual and double-lined spectroscopic binary in the Taurus star-forming region (SFR). We obtained new high angular resolution astrometry and high spectral resolution spectroscopy at Keck Observatory. The new data lead to a significant revision of previously published orbital parameters. In particular, we find that the masses of the primary and secondary are 0.86 ± 0.11 and 0.55 ± 0.05 M☉, respectively, smaller than previously reported, and that the system lies 158.7 ± 3.9 pc from the sun, further than previously reported