Hebb L.,AstronomyVanderbilt University |
Cegla H.M.,AstronomyVanderbilt University |
Cegla H.M.,Vanderbilt University |
Cegla H.M.,Queen's University of Belfast |
And 5 more authors.
Astronomy and Astrophysics | Year: 2011
Aims. We present a double-lined orbit solution for MML 53, the recently discovered low-mass pre-main sequence eclipsing binary. Methods. Using high-resolution spectra from the SMARTS 1.5 m echelle spectrograph, we measure precise radial velocities and derive the orbital parameters of the system. Results. The 2.1 d orbit of the eclipsing pair is circular, and we find the minimum masses of the eclipsing components to be M1sin3i = 0.97 M™ and M2sin3i = 0.84 M™, with formal uncertainties of 2.0% and an additional systematic uncertainty of 2.5% most likely caused by large star spots on the primary star. MML 53 has been previously identified as a member of the Upper Centaurus Lupus (UCL) star forming region (age ∼15 Myr). The systemic radial velocity from our orbit solution, vγ = +1.4 ± 0.3 ± 0.8 km s-1 (statistical and systematic), is also consistent with kinematic membership in this association. In addition, we detect a change in vγ between 2006 and 2009 providing further evidence for the presence of a the third body in a wide (several year) orbit. © 2011 ESO.