Eclipsing binary stars in the Large Magellanic Cloud: results from the EROS-2, OGLE and VMC surveys

TitleEclipsing binary stars in the Large Magellanic Cloud: results from the EROS-2, OGLE and VMC surveys
Publication TypeJournal Article
Year of Publication2014
AuthorsMuraveva, T, Clementini, G, Maceroni, C, Evans, C J, Moretti, M I, Cioni, M-R L, Marquette, J B, Ripepi, V, de Grijs, R, Groenewegen, M A T, Piatti, A E, van Loon, J T
Keywordsbinaries: eclipsing, Magellanic Clouds, surveys, techniques: photometric

{We present a catalogue of 1768 eclipsing binary stars (EBs) detected in the Large Magellanic Cloud (LMC) by the second generation of the EROS survey (hereinafter EROS-2); 493 of them are new discoveries located in outer regions (out of the central bar) of the LMC. These sources were originally included in a list of candidate classical Cepheids (CCs) extracted from the EROS-2 catalogue on the basis of the period (0.89 łt} P$_{EROS}$ łt} 15.85 d) versus luminosity [13.39 łt} łt}B$_{EROS}${\gt} łt} 17.82 mag] diagram. After visual inspection of the light curves we reclassified them as eclipsing binaries. They have blue colours (B$_{EROS}$ - R$_{EROS}$ łt} 0.2 mag) hence we classed them as hot eclipsing binaries (HEBs) containing hot massive components: main sequence (MS) stars or blue giants. We present K$_{s}$-band light curves for 999 binaries from our sample that have a counterpart in the VISTA near-infrared ESO public survey of the Magellanic Clouds system (VMC). We provide spectral classifications of 13 HEBs with existing spectroscopy. We divided our sample into contact-like binaries and detached/semi-detached systems based on both visual inspection and the parameters of the Fourier decomposition of the light curves and analysed the period-luminosity (PL) relations of the contact-like systems using the R$_{EROS}$ and K$_{s}$ magnitudes at maximum light. The contact-like binaries in our sample do not follow PL relations. We analysed the sample of contact binaries from the OGLE III catalogue and confirmed that PL$_{I}$ and PL\_$\{$K\_s$\}$ sequences are defined only by eclipsing binaries containing a red giant component. }