Research Note

Refined masses and distance of the young binary Haro 1-14 C^⋆

¹ UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France
e-mail: jean-baptiste.lebouquin@obs.ujf-grenoble.fr
² European Southern Observatory, 85748 Garching by München, Germany
³ Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA
⁴ The CHARA Array of Georgia State University, Mount Wilson Observatory, Mount Wilson, CA 91023, USA

Received: 28 October 2013
Accepted: 13 December 2013

Abstract

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 8 m telescopes of the Very Large Telescope Interferometer.

Results. The derived masses are M_a = 0.905 ± 0.043 M_⊙ and M_b = 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 φ_a = 0.13 ± 0.01 mas and φ_b = 0.10 ± 0.01 mas (corresponding to R_a = 1.50 R_⊙ and R_b = 1.13 R_⊙) and a visual extinction of A_v ≈ 1.75. Although the revised orbit has a nearly edge-on 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.