PHYSICS OF ECLIPSING BINARIES. II. TOWARD THE INCREASED MODEL FIDELITY

The precision of photometric and spectroscopic observations has been systematically improved in the last decade, mostly thanks to space-borne photometric missions and ground-based spectrographs dedicated to finding exoplanets. The field of eclipsing binary stars strongly benefited from this development. Eclipsing binaries serve as critical tools for determining fundamental stellar properties (masses, radii, temperatures, and luminosities), yet the models are not capable of reproducing observed data well, either because of the missing physics or because of insufficient precision. This led to a predicament where radiative and dynamical effects, insofar buried in noise, started showing up routinely in the data, but were not accounted for in the models. PHOEBE (PHysics Of Eclipsing BinariEs; http://phoebe-project.org) is an open source modeling code for computing theoretical light and radial velocity curves that addresses both problems by incorporating missing physics and by increasing the computational fidelity. In particular, we discuss triangulation as a superior surface discretization algorithm, meshing of rotating single stars, light travel time effects, advanced phase computation, volume conservation in eccentric orbits, and improved computation of local intensity across the stellar surfaces that includes the photon-weighted mode, the enhanced limb darkening treatment, the better reflection treatment, and Doppler boosting. Here we present the concepts on which PHOEBE is built and proofs of concept that demonstrate the increased model fidelity.

[1]  S. Bloemen,et al.  Pulsating red giant stars in eccentric binary systems discovered fromKeplerspace based photometry , 2017 .

[2]  P. Brown,et al.  INTERPRETING FLUX FROM BROADBAND PHOTOMETRY , 2016, 1608.02599.

[3]  J. Laskar,et al.  NOMINAL VALUES FOR SELECTED SOLAR AND PLANETARY QUANTITIES: IAU 2015 RESOLUTION B3 , 2016, 1605.09788.

[4]  Laszlo Sturmann,et al.  Spectroscopy, MOST Photometry, and Interferometry of MWC 314: Is it an LBV or an interacting binary? , 2015, 1510.00324.

[5]  Christina Freytag,et al.  Radiative Processes In Astrophysics , 2016 .

[6]  Luca Casagrande,et al.  Synthetic stellar photometry – I. General considerations and new transformations for broad-band systems , 2014, 1407.6095.

[7]  P. Gaulme,et al.  SURFACE ACTIVITY AND OSCILLATION AMPLITUDES OF RED GIANTS IN ECLIPSING BINARIES , 2014, 1402.3027.

[8]  J. De Ridder,et al.  Pulsating red giant stars in eccentric binary systems discovered from Kepler space-based photometry. A sample study and the analysis of KIC 5006817 , 2013, 1312.4500.

[9]  R. Wilson,et al.  UNIFICATION OF BINARY STAR EPHEMERIS SOLUTIONS , 2013 .

[10]  R. Kudritzki,et al.  An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent , 2013, Nature.

[11]  P. Gaulme,et al.  RED GIANTS IN ECLIPSING BINARY AND MULTIPLE-STAR SYSTEMS: MODELING AND ASTEROSEISMIC ANALYSIS OF 70 CANDIDATES FROM KEPLER DATA , 2013, 1303.1197.

[12]  F. Mullally,et al.  A CLASS OF ECCENTRIC BINARIES WITH DYNAMIC TIDAL DISTORTIONS DISCOVERED WITH KEPLER , 2012, 1203.6115.

[13]  S. Bloemen,et al.  Mass ratio from Doppler beaming and Rømer delay versus ellipsoidal modulation in the Kepler data of KOI-74 , 2012, 1202.5553.

[14]  J. H. J. de Bruijne,et al.  Science performance of Gaia, ESA’s space-astrometry mission , 2012, 1201.3238.

[15]  P. Wood,et al.  Eccentric ellipsoidal red giant binaries in the LMC: complete orbital solutions and comments on interaction at periastron , 2012, 1201.1043.

[16]  Michael S. Bessell,et al.  Spectrophotometric Libraries, Revised Photonic Passbands, and Zero Points for UBVRI, Hipparcos, and Tycho Photometry , 2011, 1112.2698.

[17]  Simon Širca,et al.  Computational Methods for Physicists , 2012 .

[18]  R. P. Butler,et al.  TWO UPPER LIMITS ON THE ROSSITER–MCLAUGHLIN EFFECT, WITH DIFFERING IMPLICATIONS: WASP-1 HAS A HIGH OBLIQUITY AND WASP-2 IS INDETERMINATE , 2011, 1106.2548.

[19]  Keivan G. Stassun,et al.  EXPECTED LARGE SYNOPTIC SURVEY TELESCOPE (LSST) YIELD OF ECLIPSING BINARY STARS , 2011, 1105.6011.

[20]  J. Telting,et al.  Kepler observations of the beaming binary KPD 1946+4340 , 2010, 1010.2747.

[21]  Howard Isaacson,et al.  Kepler Planet-Detection Mission: Introduction and First Results , 2010, Science.

[22]  Oxford,et al.  OBSERVATIONS OF DOPPLER BOOSTING IN KEPLER LIGHT CURVES , 2010, 1001.4539.

[23]  A. Gimenez,et al.  Accurate masses and radii of normal stars: modern results and applications , 2009, 0908.2624.

[24]  Abdel-Fattah Attia,et al.  A modified genetic algorithm for precise determination the geometrical orbital elements of binary stars , 2009 .

[25]  C. Moutou,et al.  Misaligned spin-orbit in the XO-3 planetary system?† , 2008, Proceedings of the International Astronomical Union.

[26]  Robert E. Wilson,et al.  Eclipsing Binary Solutions in Physical Units and Direct Distance Estimation , 2008 .

[27]  Tel Aviv,et al.  Beaming Binaries: A New Observational Category of Photometric Binary Stars , 2007, 0708.2100.

[28]  T. Borkovits,et al.  Tidal and rotational effects in the perturbations of hierarchical triple stellar systems. II. Eccentric systems : the case of AS Camelopardalis , 2007, 0707.1590.

[29]  M. Bessell.  Standard Photometric Systems , 2005 .

[30]  A. Prsa,et al.  A Computational Guide to Physics of Eclipsing Binaries. I. Demonstrations and Perspectives , 2005, astro-ph/0503361.

[31]  Gordon A. H. Walker,et al.  The MOST Asteroseismology Mission: Ultraprecise Photometry from Space , 2003 .

[32]  B. Gaudi,et al.  Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions , 2003, astro-ph/0303212.

[33]  Annie Baglin,et al.  COROT: A minisat for pionnier science, asteroseismology and planets finding , 2003 .

[34]  J. Anthony Tyson,et al.  Survey and Other Telescope Technologies and Discoveries , 2002 .

[35]  Robert Jedicke,et al.  Pan-STARRS: A Large Synoptic Survey Telescope Array , 2002, SPIE Astronomical Telescopes + Instrumentation.

[36]  Erich Hartmann,et al.  A marching method for the triangulation of surfaces , 1998, The Visual Computer.

[37]  S. M. Rucinski,et al.  On the name "over-contact binary systems" , 1997 .

[38]  Gabriel Taubin,et al.  Estimating the tensor of curvature of a surface from a polyhedral approximation , 1995, Proceedings of IEEE International Conference on Computer Vision.

[39]  Ivan Hubeny,et al.  Non-LTE line-blanketed model atmospheres of hot stars. 1: Hybrid complete linearization/accelerated lambda iteration method , 1995 .

[40]  Pat Hanrahan,et al.  Textures and radiosity: controlling emission and reflection with texture maps , 1994, SIGGRAPH.

[41]  Christopher J. Corbally,et al.  The calibration of MK spectral classes using spectral synthesis. 1: The effective temperature calibration of dwarf stars , 1994 .

[42]  M. Dworetsky,et al.  Peculiar versus Normal Phenomena in A-type and Related Stars , 1993 .

[43]  Bala R. Vatti.  A generic solution to polygon clipping , 1992, CACM.

[44]  Steven K. Feiner,et al.  Computer graphics: principles and practice (2nd ed.) , 1990 .

[45]  R. E. Wilson.  Accuracy and efficiency in the binary star reflection effect , 1990 .

[46]  Y. Avni,et al.  Generalized Roche potential for misaligned binary systems - Properties of the critical lobe , 1982 .

[47]  R. E. Wilson.  Eccentric orbit generalization and simultaneous solution of binary star light and velocity curves , 1979 .

[48]  Robert E. Wilson,et al.  Realization of Accurate Close-Binary Light Curves: Application to MR Cygni , 1971 .

[49]  J. Dommanget.  On the Evolution of Double Stars , 1967 .

[50]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[51]  M. J. D. Powell,et al.  An efficient method for finding the minimum of a function of several variables without calculating derivatives , 1964, Comput. J..

[52]  D. N. Limber.  Surface Forms and Mass Loss for the Components of Close Binaries-General Case of Non-Synchronous Rotation. , 1963 .