Probing M subdwarf metallicity with an esdK5+esdM5.5 binaryYa. V. Pavlenko, Z. H. Zhang, M. C. Gálvez-Ortiz, I. O. Kushniruk and H. R. A. JonesA&A, 582 (2015) A92DOI: https://doi.org/10.1051/0004-6361/201526810