%0 Journal Article %T New RR Lyrae variables in binary systems. %+ Institut d'Astrophysique de Paris (IAP) %A Hajdu, G. %A Catelan, M. %A Jurcsik, J. %A Dekany, I. %A Drake, A. J. %A Marquette, J. -B. %< avec comité de lecture %J Mon. Not. R. Astron. Soc. %V 449 %P L113-L117 %8 2015 %D 2015 %Z 1502.01318 %Z 2015MNRAS.449L.113H %R 10.1093/mnrasl/slv024 %K methods: data analysis %K techniques: photometric %K binaries: general %K stars: fundamental parameters %K stars: oscillations %K stars: variables: RR Lyrae %K Astrophysics - Solar and Stellar Astrophysics %K Astrophysics - Instrumentation and Methods for Astrophysics %Z Sciences of the Universe [physics] %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles %X Despite their importance, very few RR Lyrae (RRL) stars have been known to reside in binary systems. We report on a search for binary RRL in the OGLE-III Galactic bulge data. Our approach consists in the search for evidence of the light-travel time effect in so-called observed minus calculated (O-C) diagrams. Analysis of 1952 well-observed fundamental-mode RRL in the OGLE-III data revealed an initial sample of 29 candidates. We used the recently released OGLE-IV data to extend the baselines up to 17 yr, leading to a final sample of 12 firm binary candidates. We provide O-C diagrams and binary parameters for this final sample, and also discuss the properties of eight additional candidate binaries whose parameters cannot be firmly determined at present. We also estimate that ≳ 4 per cent of the RRL reside in binary systems. %G English %2 https://insu.hal.science/insu-03644972/document %2 https://insu.hal.science/insu-03644972/file/slv024.pdf %L insu-03644972 %U https://insu.hal.science/insu-03644972 %~ INSU %~ CNRS %~ IAP %~ SORBONNE-UNIVERSITE %~ SU-INF-2018 %~ SU-SCIENCES %~ SU-TI %~ ALLIANCE-SU