Session 49 - Young Stellar Objects.
Display session, Tuesday, January 14
Metropolitan Ballroom,

## [49.07] The Pre-Main-Sequence Double-Lined Spectroscopic, Binary NTT 155913-2233

L. Prato, M. Simon (SUNY, Stony Brook)

Using high resolution, near infrared spectroscopy, we detected the cool secondary component of the visual-light spectroscopic binary in the pre-main-sequence system NTT 155913-2233. We identify approximate spectral types of K5 and M5 for the stars in the now double-lined spectroscopic binary (SB2), and K5 for the tertiary component at 0.29''. We find a mass ratio of 2.1\pm0.24 for the SB2. From the mass function determined by Mathieu (1994) we obtain lower limits for the primary and secondary masses of 1.1\pm0.2 and 0.5\pm0.1, respectively. Using fluxes from our model fit to the data, together with the spectral types and the mass ratio of the components, we are able to plot NTT 155913-2233 as a coeval system only on the Swenson et al. (1994) pre-main-sequence evolutionary tracks.