New RR Lyrae variables in binary systems

Abstract

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 years, 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 8 additional candidate binaries whose parameters cannot be firmly determined at present. We also estimate that $\gtrsim 4$ per cent of the RRL reside in binary systems.

MNRAS Letters, in press

References in corpus (26)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
• Probing the Outer Galactic halo with RR Lyrae from the Catalina Surveys
• VVV Survey Near-Infrared Photometry of Known Bulge RR Lyrae stars: the Distance to the Galactic Center and Absence of a Barred Distribution of the Metal-Poor Population
• The Luminosities and Distance Scales of Type II Cepheid and RR Lyrae variables
• Accurate dynamical mass determination of a classical Cepheid in an eclipsing binary system
• Distance Scale Zero-Points from Galactic RR Lyrae Star Parallaxes
• First Kepler results on RR Lyrae stars
• RR-Lyrae-type pulsations from a 0.26-solar-mass star in a binary system
• Exploring the Variable Sky with LINEAR. II. Halo Structure and Substructure Traced by RR Lyrae Stars to 30 kpc
• Discovery of $\sim$ 9,000 new RR Lyrae in the Southern Catalina Surveys
• The Konkoly Blazhko Survey: Is light-curve modulation a common property of RRab stars?
• Evidence for a Milky Way Tidal Stream Reaching Beyond 100 kpc
• RR Lyrae variables: visual and infrared luminosities, intrinsic colours, and kinematics
• Evidence for an Overluminosity of the Variable Star RR Lyr, and a Revised Distance to the LMC
• Astrometric planet search around southern ultracool dwarfs I: First results, including parallaxes of 20 M8-L2 dwarfs
• Pulsation models for the 0.26M_sun star mimicking RR Lyrae pulsator. Model survey for the new class of variable stars
• On the Predicted and Observed Color Boundaries of the RR Lyrae Instability Strip as a Function of Metallicity
• Double-mode RR Lyrae Variables: Pulsational Masses Revisited
• Long-term photometric monitoring of Messier 5 variables: II. Blazhko stars
• The Araucaria Project. OGLE-LMC-CEP-1718: An exotic eclipsing binary system composed of two classical overtone Cepheids in a 413-day orbit
• Seven New Carbon-Enhanced Metal-Poor RR Lyrae Stars
• Modelling the nucleosynthetic properties of carbon-enhanced metal-poor RR Lyrae stars
• In search of RR Lyrae type stars in eclipsing binary systems. OGLE052218.07-692827.4: an optical blend
• Pulsational and evolutionary analysis of the double-mode RR Lyrae star BS Com
• A search for binary candidates among the fundamental mode RR Lyrae stars observed by Kepler

Cited by in corpus (30)

• Gaia Data Release 1 - The Cepheid & RR Lyrae star pipeline and its application to the south ecliptic pole region
• Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2 - I. Binarity from proper motion anomaly
• The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis
• Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2 -- II. Resolved common proper motion pairs
• The occurrence of Binary Evolution Pulsators in the classical instability strip of RR Lyrae and Cepheid variables
• Evidence for Galactic disc RR~Lyrae stars in the Solar neighbourhood
• First results on RR Lyrae stars with the TESS space telescope: untangling the connections between mode content, colors and distances
• An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2
• Cyclic variations in O-C diagrams of field RR Lyrae stars as a result of LiTE
• On the Use of Field RR Lyrae as Galactic Probes. III. The $\alpha$-element abundances
• RR Lyrae From Binary Evolution: Abundant, Young and Metal-Rich
• Blazhko effect in the Galactic bulge fundamental mode RR~Lyrae stars I: Incidence rate and differences between modulated and non-modulated stars
• New analysis of the light time effect in TU Ursae Majoris
• Studies of RR Lyrae Variables in Binary Systems. I.: Evidence of a Trimodal Companion Mass Distribution
• KIC 2831097 - A 2-year orbital-period RR Lyrae binary candidate
• Luminosities and infrared excess in Type II and anomalous Cepheids in the Large and Small Magellanic Clouds
• Candidates for RR~Lyrae in binary systems from the OGLE Galactic bulge survey
• On the variation of light curve parameters of RR Lyrae variables at multiple wavelengths
• Period Change Rates in Large Magellanic Cloud Cepheids Revisited
• The Blazhko effect and additional excited modes in RR Lyrae stars
• A cautionary tale of interpreting O-C diagrams: period instability in a classical RR Lyr Star Z CVn mimicking as a distant companion
• A 5% measurement of the gravitational constant in the Large Magellanic Cloud
• The SERMON project: 48 new field Blazhko stars and an investigation of modulation-period distribution
• Humps and bumps: The effects of shocks on the optical light curves of fundamental-mode RR Lyrae stars
• Variable stars in the residual light curves of OGLE-IV eclipsing binaries towards the Galactic Bulge
• The elusive chase for the first RR Lyr star in a binary system: the case of KIC 2831097
• Rare Find: Discovery and chemo-dynamical properties of two s-process enhanced RR Lyrae stars
• Non-evolutionary effects on period change in Magellanic Cepheids I. New binary systems revealed from Light Travel Time Effect
• Matching seismic masses for RR Lyrae-type and oscillating red horizontal-branch stars in M4
• IY Lyr: A Thick-Disk first-overtone RR Lyrae Star with a Possible Neutron Star Companion