BG Ind: the nearest doubly eclipsing, compact hierarchical quadruple system

Abstract

BG Ind is a well studied, bright, nearby binary consisting of a pair of F stars in a 1.46-day orbit. We have discovered in the TESS lightcurve for TIC 229804573 (aka BG Ind) a second eclipsing binary in the system with a 0.53-day. Our subsequent analyses of the recent TESS and archival ground-based photometric and radial velocity data, reveal that the two binaries are gravitationally bound in a 721-day period, moderately eccentric orbit. We present the results of a joint spectro-photodynamical analysis of the eclipse timing variation curves of both binaries based on TESS and ground-based archival data, the TESS lightcurve, archival radial velocity data and the spectral energy distribution, coupled with the use of PARSEC stellar isochrones. We confirm prior studies of BG Ind which found that the brighter binary A consists of slightly evolved F-type stars with refined masses of 1.32 and 1.43 $M_{\odot }$, and radii of 1.59 and 2.34 $R_{\odot }$. The previously unknown binary B has two less massive stars of 0.69 and 0.64 $M_{\odot }$ and radii of 0.64 and 0.61 $R_{\odot }$. Based on a number of different arguments which we discuss, we conclude that the three orbital planes are likely aligned to within 17${}^{\circ }$.

17 pages. Accepted for publication in MNRAS

References in corpus (37)

• Gaia Data Release 2. Summary of the contents and survey properties
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The Transiting Exoplanet Survey Satellite
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• The WASP Project and the SuperWASP Cameras
• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• The TESS Input Catalog and Candidate Target List
• First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
• The Geneva-Copenhagen Survey of the Solar neighbourhood III. Improved distances, ages, and kinematics
• Correcting systematic effects in a large set of photometric lightcurves
• New Grids of ATLAS9 Model Atmospheres
• Quantifying the Uncertainty in the Orbits of Extrasolar Planets
• Stellar and substellar companions of nearby stars from Gaia DR2 - Binarity from proper motion anomaly
• The Hipparcos-Gaia Catalog of Accelerations
• A fast hybrid algorithm for exoplanetary transit searches
• Eclipsing Binary Stars as Benchmarks for Trigonometric Parallaxes in the Gaia Era
• The Updated Multiple Star Catalog
• Eclipse Timing Variation Analyses of Eccentric Binaries with Close Tertiaries in the Kepler field
• Mass and p-factor of the type II Cepheid OGLE-LMC-T2CEP-098 in a binary system
• Photodynamical analysis of the triply eclipsing hierarchical triple system EPIC 249432662
• TIC 168789840: A Sextuply-Eclipsing Sextuple Star System
• Planet Hunters TESS II: Findings from the first two years of TESS
• TICs 167692429 and 220397947: The first compact hierarchical triple stars discovered with TESS
• EPIC 220204960: A Quadruple Star System Containing Two Strongly Interacting Eclipsing Binaries
• Mass loss and orbital period decrease in detached chromospherically active binaries
• Dancing twins: stellar hierarchies that formed sequentially?
• VW LMi: tightest quadruple system known. Light-time effect and possible secular changes of orbits
• New orbits based on speckle interferometry at SOAR. II
• Doubly eclipsing systems
• EPIC 219217635: A Doubly Eclipsing Quadruple System Containing an Evolved Binary
• Updated study of the quintuple system V994 Herculis
• Kappa Fornaci, a triple radio-star
• Secular changes in the orbits of the quadruple system VW LMi
• TIC 278956474: Two close binaries in one young quadruple system, identified by \textit{TESS}
• Analysis of eclipsing binaries in multiple stellar systems: the case of V1200 Centauri
• Absolute properties of BG Ind - a bright F3 system just leaving the Main Sequence
• The Spectroscopic Orbits of Three Double-lined Eclipsing Binaries: I. BG Ind, IM Mon, RS Sgr

Cited by in corpus (15)

• Six New Compact Triply Eclipsing Triples Found With TESS
• Triply eclipsing triple stars in the northern TESS fields: TICs 193993801, 388459317 and 52041148
• Planet Hunters TESS IV: A massive, compact hierarchical triple star system TIC 470710327
• A Study of Nine Triply Eclipsing Triples
• Multiply eclipsing candidates from the TESS satellite
• Von Zeipel - Lidov - Kozai cycles in action: $Kepler$ triples with eclipse depth variations: KICs 6964043, 5653126, 5731312 and 8023317
• TIC 114936199: A Quadruple Star System with a 12-day Outer Orbit Eclipse
• V994 Her: A Unique Triply Eclipsing Sextuple Star System
• Detection of seven 2+2 doubly eclipsing quadruple systems
• Ten new, ultracompact triply eclipsing triple star systems
• The complex dynamical past and future of double eclipsing binary CzeV343: misaligned orbits and period resonance
• Rediscussion of eclipsing binaries. Paper V. The triple system V455 Aurigae
• TIC 454140642: A Compact, Coplanar, Quadruple-lined Quadruple Star System Consisting of Two Eclipsing Binaries
• The Visual Survey Group: A Decade of Hunting Exoplanets and Unusual Stellar Events with Space-Based Telescopes
• A 2+1+1 quadruple star system containing the most eccentric, low-mass, short-period, eclipsing binary known