Refined masses and distance of the young binary Haro 1-14 C ? (Research Note)

Aims. We aim to refine the dynamical masses of the individual component of the low-mass pre-main sequence binary Haro 1-14C. Methods. We combine the data of the preliminary orbit presented previously with new interferometric observations obtained with the four 8m telescopes of the Very Large Telescope Interferometer. Results. The derived masses are Ma = 0.905 ± 0.043 M and Mb = 0.308 ± 0.011 M for the primary and secondary components, respectively. This is about five times better than the uncertainties of the preliminary orbit. Moreover, the possibility of larger masses is now securely discarded. The new dynamical distance, d = 96 ± 9 pc, is smaller than the distance to the Ophiuchus core with a significance of 2.6σ. Fitting the spectral energy distribution yields apparent diameters of φa = 0.13±0.01 mas and φb = 0.10±0.01 mas (corresponding to Ra = 1.50 R and Rb = 1.13 R ) and a visual extinction of Av ≈ 1.75. Although the revised orbit has a nearly edgeon geometry, the system is unlikely to be a long-period eclipsing binary. Conclusions. The secondary in Haro 1-14C is one of the few low-mass, pre-main sequence stars with an accurately determined dynamical mass and distance.