Spectroscopic and photometric analysis of the early-type spectroscopic binary HD 161853 in the centre of an H ii regionR. Gamen, C. Putkuri, N. I. Morrell, R. H. Barbá, J. I. Arias, J. Maíz Apellániz, N. R. Walborn, A. Sota and E. J. AlfaroA&A, 584 (2015) A7DOI: https://doi.org/10.1051/0004-6361/201425558