@article{MTMT:34497324, title = {TIC 184 743 498: the first tri-axial stellar pulsator}, url = {https://m2.mtmt.hu/api/publication/34497324}, author = {Zhang, Valencia and Rappaport, Saul and Jayaraman, Rahul and Kurtz, Donald W. and Handler, Gerald and Fuller, James and Borkovits, Tamás}, doi = {10.1093/mnras/stae010}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {528}, unique-id = {34497324}, issn = {0035-8711}, abstract = {We have discovered a $\\delta$ Scuti pulsator in a tight binary (P = 1.053 d) with nine pulsation modes whose frequencies are between 38 and 56 d$^{-1}$. Each of these modes exhibits amplitude modulations and $\\pi$-rad phase shifts twice per orbital cycle. Five of these modes exhibit amplitude and phase shifts that are readily explained by dipole pulsations along an axis that is aligned with the binary's tidal axis. The novelty of the system lies in the remaining four pulsation modes, which we show are dipole pulsations along an axis that is perpendicular to both the tidal axis and the binary's orbital angular momentum axis. There are additionally two pulsation modes whose amplitudes and phases do not change significantly with orbital phase; they are explained as dipole modes along an axis aligned with the orbital/rotation axis. Hence, we propose that TIC 184743498 is a tri-axial pulsator, the first of its kind.}, keywords = {Astrophysics - Solar and Stellar Astrophysics}, year = {2024}, eissn = {1365-2966}, pages = {3378-3391}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X} } @article{MTMT:34351619, title = {101 Eclipsing Quadruple Star Candidates Discovered in TESS Full Frame Images}, url = {https://m2.mtmt.hu/api/publication/34351619}, author = {Kostov, Veselin B. and Powell, Brian P. and Rappaport, Saul A. and Borkovits, Tamás and Gagliano, Robert and Jacobs, Thomas L. and Jayaraman, Rahul and Kristiansen, Martti H. and LaCourse, Daryll M. and Mitnyan, Tibor and Omohundro, Mark and Orosz, Jerome and Pál, András and Schmitt, Allan R. and Schwengeler, Hans M. and Terentev, Ivan A. and Torres, Guillermo and Barclay, Thomas and Vanderburg, Andrew and Welsh, William}, doi = {10.1093/mnras/stad2947}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {527}, unique-id = {34351619}, issn = {0035-8711}, abstract = {We present our second catalog of quadruple star candidates, containing 101 systems discovered in TESS Full-Frame Image data. The targets were initially detected as eclipsing binary stars with the help of supervised machine learning methods applied to sectors Sectors 1 through 54. A dedicated team of citizen scientists subsequently identified through visual inspection two sets of eclipses following two different periods. All 101 systems presented here pass comprehensive photocenter motion tests confirming that both sets of eclipses originate from the target star. Some of the systems exhibit prominent eclipse time variations suggesting dynamical interactions between the two component binary stars. One target is an eclipsing quintuple candidate with a (2+1)+2 hierarchical configuration, such that the (2+1) subsystem produces eclipses on the triple orbit as well. Another has recently been confirmed as the second shortest period quadruple reported to date. This catalog provides ephemerides, eclipse depths and durations, sample statistics, and highlights potentially interesting targets for future studies.}, keywords = {Astrophysics - Solar and Stellar Astrophysics; binaries: eclipsing; binaries (including multiple): close}, year = {2024}, eissn = {1365-2966}, pages = {3995-4017}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938} } @article{MTMT:34493626, title = {Observational Detection of Higher-Order Secular Perturbations in Tight Hierarchical Triple Stars}, url = {https://m2.mtmt.hu/api/publication/34493626}, author = {Borkovits, Tamás and Mitnyan, Tibor}, doi = {10.3390/universe9110485}, journal-iso = {UNIVERSE-BASEL}, journal = {UNIVERSE}, volume = {9}, unique-id = {34493626}, abstract = {In this work, we search for observational evidence of higher-order secular perturbations in three eclipsing binaries. These are slightly eccentric binaries, and they form the inner pairs of tight, compact, hierarchical triple star systems. Simultaneously, we analyze the high-precision satellite (Kepler and TESS) light curves; eclipse timing variations; combined spectral energy distributions (through catalog passband magnitudes); and, where available, radial velocities of KICs 9714358, 5771589, and TIC 219885468. Besides the determination of the robust astrophysical and dynamical properties of the three systems, we find evidence that the observed unusual eclipse timing variations of KIC 9714358 are a direct consequence of the octupole-order secular eccentricity perturbations forced by unusual, resonant behavior between the lines of the apsides of the inner and outer orbital ellipses. We also show that, despite its evident cyclic eclipse depth variations, KIC 5771589 is an almost perfectly coplanar system (to within 0.3∘), and we explain the rapid eclipse depth variations with the grazing nature of the eclipses. Finally, we find that the inner pair of TIC 219885468 consists of two twin stars; hence, in this triple there are no octupole-order three-body perturbations. Moreover, we show that this triple is also coplanar on the same level as the former one, but due to its deep eclipses, it does not exhibit eclipse depth variations. We intend to follow this work up with further analyses and a quantitative comparison of the theoretical and the observed perturbations.}, keywords = {Astrophysics - Solar and Stellar Astrophysics}, year = {2023}, eissn = {2218-1997}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938} } @CONFERENCE{MTMT:34352771, title = {Then and now: A new look on the eclipse timing variations of hierarchical triple star candidates in the primordial Kepler-field, revisited by TESS}, url = {https://m2.mtmt.hu/api/publication/34352771}, author = {Borkovits, Tamás and Rappaport, S. A. and Mitnyan, Tibor and Barna, Biro Imre and Csanyi, Istvan and Forró, Adrienn and Hajdu, Tamás and Sztakovics, János and Pál, András}, booktitle = {7th International Conference in Astronomy, Astrophysics, Space and Planetary Sciences – ZAC2023}, unique-id = {34352771}, abstract = {A former analysis of eclipse timing variation (ETV) curves of eclipsing binaries (EB) observed by Kepler spacecraft during its ~4-yr-long prime mission has led to the discovery and characterization of 222 hierarchical triple star systems with different confidence levels. Although the prime Kepler-mission ended in 2013 (almost exactly ten years ago), the TESS space telescope revisited the original Kepler-field in the summers of 2019, 2021 and 2022, allowing to extend the time-base of high precision times of minima observations for a substantially longer interval. In this talk, I present our new analysis about the extended ETV curves of the formerly identified triple star candidates and many other Kepler EBs. Besides the confirmations of the former findings and/or the improvements of the triple systems' orbital properties, the extended time-base allowed us to identify several new, longer outer period triple systems on one side, and it made also possible a more detailed study of the dynamical perturbations in the tightest triple stars, on the other side.}, year = {2023}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938; Hajdu, Tamás/0000-0001-8060-2367} } @article{MTMT:34351591, title = {Four new compact triply eclipsing triples found with Gaia and TESS}, url = {https://m2.mtmt.hu/api/publication/34351591}, author = {Czavalinga, Donát Róbert and Borkovits, Tamás and Mitnyan, Tibor and Rappaport, Saul A. and Pál, András}, doi = {10.1093/mnras/stad2759}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {526}, unique-id = {34351591}, issn = {0035-8711}, abstract = {This paper presents a comprehensive analysis of four triply eclipsing triple star systems, namely TIC 88206187, TIC 14839347, TIC 298714297, and TIC 66893949. The four systems with third-body eclipses were found in the TESS light curves from among a sample of ~400 matches between known eclipsing binaries and the Gaia DR3 Non-Single Star solution data base. We combined photometric light curves, eclipse timing variations, archival spectral energy distributions, and theoretical evolution tracks in a robust photodynamical analysis to determine the orbital and system parameters. The triples have outer periods of 52.9 d, 85.5 d, 117 d, and 471 d, respectively. All dozen stars have masses ≲ 2.6 M⊙. The systems are quite flat with mutual inclination angles between the inner and outer orbital planes that are all ≲ 4°. The outer mass ratios (q ≡ M3/Mbin) range from 0.39 to 0.76, consistent with our earlier collection of compact triply eclipsing triples. TIC 88206187 exhibits a fractional radius of the outer tertiary component (rB ≡ RB/aout) exceeding 0.1 (only the third such system known), and we consider its future evolution. Finally, we compare our photodynamical analysis results and the orbital parameters given in the Gaia DR3 NSS solutions, indicating decent agreement, but with the photodynamical results being more accurate.}, keywords = {Astrophysics - Solar and Stellar Astrophysics; binaries: close; binaries: eclipsing; stars: individual: TIC 14839347; TIC 66893949; TIC 88206187; TIC 298714297}, year = {2023}, eissn = {1365-2966}, pages = {2830-2845}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938} } @article{MTMT:34061567, title = {BU Canis Minoris - the most compact known flat doubly eclipsing quadruple system}, url = {https://m2.mtmt.hu/api/publication/34061567}, author = {Pribulla, Theodor and Borkovits, Tamás and Jayaraman, Rahul and Rappaport, Saul and Mitnyan, Tibor and Zasche, Petr and Komžík, Richard and Pál, András and Uhlař, Robert and Mašek, Martin and Henzl, Zbyněk and Bíró, Imre Barna and Csányi, István and Stuik, Remko and Kristiansen, Martti H. and Schwengeler, Hans M. and Gagliano, Robert and Jacobs, Thomas L. and Omohundro, Mark and Kostov, Veselin and Powell, Brian P. and Terentev, Ivan A. and Vanderburg, Andrew and LaCourse, Daryll and Rodriguez, Joseph E. and Bakos, Gáspár and Csubry, Zoltán and Hartman, Joel}, doi = {10.1093/mnras/stad2015}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {524}, unique-id = {34061567}, issn = {0035-8711}, abstract = {We have found that the 2+2 quadruple star system BU CMi is currently the most compact quadruple system known, with an extremely short outer period of only 121 days. The previous record holder was TIC 219006972 (Kostov et al. 2023), with a period of 168 days. The quadruple nature of BU CMi was established by Volkov et al. (2021), but they misidentified the outer period as 6.6 years. BU CMi contains two eclipsing binaries (EBs), each with a period near 3 days, and a substantial eccentricity of ≃ 0.22. All four stars are within ~0.1 M⊙ of 2.4 M⊙. Both binaries exhibit dynamically driven apsidal motion with fairly short apsidal periods of ≃ 30 years, thanks to the short outer orbital period. The outer period of 121 days is found both from the dynamical perturbations, with this period imprinted on the eclipse timing variations (ETV) curve of each EB by the other binary, and by modeling the complex line profiles in a collection of spectra. We find that the three orbital planes are all mutually aligned to within 1 degree, but the overall system has an inclination angle near 83.5○. We utilize a complex spectro-photodynamical analysis to compute and tabulate all the interesting stellar and orbital parameters of the system. Finally, we also find an unexpected dynamical perturbation on a timescale of several years whose origin we explore. This latter effect was misinterpreted by Volkov et al. (2021) and led them to conclude that the outer period was 6.6 years rather than the 121 days that we establish here.}, keywords = {Astrophysics - Solar and Stellar Astrophysics; binaries: eclipsing; binaries: spectroscopic; stars: individual: BU CMi}, year = {2023}, eissn = {1365-2966}, pages = {4220-4238}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938} } @article{MTMT:33771241, title = {TIC 219006972: a compact, coplanar quadruple star system consisting of two eclipsing binaries with an outer period of 168 d}, url = {https://m2.mtmt.hu/api/publication/33771241}, author = {Kostov, Veselin B and Borkovits, Tamás and Rappaport, Saul A and Powell, Brian P and Pál, András and Jacobs, Thomas L and Gagliano, Robert and Kristiansen, Martti H and LaCourse, Daryll M and Moe, Maxwell and Omohundro, Mark and Schmitt, Allan R and Schwengeler, Hans M and Terentev, Ivan A and Vanderburg, Andrew}, doi = {10.1093/mnras/stad941}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {522}, unique-id = {33771241}, issn = {0035-8711}, abstract = {We present the discovery of a new highly compact quadruple star system, TIC 219006972, consisting of two eclipsing binary stars with orbital periods of 8.3 and 13.7 d, and an outer orbital period of only 168 d. This period is a full factor of 2 shorter than the quadruple with the shortest outer period reported previously, VW LMi, where the two binary components orbit each other every 355 d. The target was observed by Transiting Exoplanet Survey Satellite in full-frame images in sectors 14–16, 21–23, 41, 48, and 49, and produced two sets of primary and secondary eclipses. These show strongly non-linear eclipse timing variations (ETVs) with an amplitude of ∼0.1 d, where the ETVs of the primary and secondary eclipses and of the two binaries are all largely positively correlated. This highlights the strong dynamical interactions between the two binaries and confirms the compact quadruple configuration of TIC 219006972. The two eclipsing binaries are nearly circular, whereas the quadruple system has an outer eccentricity of about 0.25. The entire system is nearly edge-on, with a mutual orbital inclination between the two eclipsing binary star systems of about 1 deg.}, year = {2023}, eissn = {1365-2966}, pages = {90-101}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Jacobs, Thomas L/0000-0003-3988-3245} } @article{MTMT:33720976, title = {V994 Herculis: a unique triply eclipsing sextuple star system}, url = {https://m2.mtmt.hu/api/publication/33720976}, author = {Zasche, P. and Borkovits, Tamás and Jayaraman, R. and Rappaport, S. A. and Brož, M. and Vokrouhlický, D. and Bíró, Imre Barna and Hegedüs, T. and Kiss, Z. T. and Uhlař, R. and Schwengeler, H. M. and Pál, András and Mašek, M. and Howell, S. B. and Dallaporta, S. and Munari, U. and Gagliano, R. and Jacobs, T. and Kristiansen, M. H. and LaCourse, D. and Omohundro, M. and Terentev, I. and Vanderburg, A. and Henzl, Z. and Powell, B. P. and Kostov, V. B.}, doi = {10.1093/mnras/stad328}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {520}, unique-id = {33720976}, issn = {0035-8711}, abstract = {We report the discovery with the Transiting Exoplanet Survey Satellite (TESS) of a third set of eclipses from V994 Herculis (V994 Her, TIC 424508303), previously only known as a doubly eclipsing system. The key implication of this discovery and our analyses is that V994 Her is the second fully characterized (2+2) + 2 sextuple system, in which all three binaries eclipse. In this work, we use a combination of ground-based observations and TESS data to analyse the eclipses of binaries A and B in order to update the parameters of the inner quadruple's orbit (with a derived period of 1062 ± 2 d). The eclipses of binary C that were detected in the TESS data were also found in older ground-based observations, as well as in more recently obtained observations. The eclipse timing variations of all three pairs were studied in order to detect the mutual perturbations of their constituent stars, as well as those of the inner pairs in the (2 + 2) core. At the longest periods they arise from apsidal motion, which may help constraining parameters of the component stars' internal structure. We also discuss the relative proximity of the periods of binaries A and B to a 3:2 mean motion resonance. This work represents a step forward in the development of techniques to better understand and characterize multiple star systems, especially those with multiple eclipsing components.}, keywords = {Astrophysics - Solar and Stellar Astrophysics; binaries: close; binaries: eclipsing; stars: individual: TIC 424508303; V994 Her; sextuple system; (stars): sextuple system}, year = {2023}, eissn = {1365-2966}, pages = {3127-3142}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X} } @article{MTMT:33720973, title = {A study of nine compact triply eclipsing triples}, url = {https://m2.mtmt.hu/api/publication/33720973}, author = {Rappaport, S. A. and Borkovits, Tamás and Gagliano, R. and Jacobs, T. L. and Tokovinin, A. and Mitnyan, Tibor and Komžík, R. and Kostov, V. B. and Powell, B. P. and Torres, G. and Terentev, I. and Omohundro, M. and Pribulla, T. and Vanderburg, A. and Kristiansen, M. H. and Latham, D. and Schwengeler, H. M. and LaCourse, D. and Bíró, Imre Barna and Csányi, I. and Czavalinga, Donát Róbert and Garai, Zoltán and Pál, András and Rodriguez, J. E. and Stevens, D. J.}, doi = {10.1093/mnras/stad367}, journal-iso = {MON NOT R ASTRON SOC}, journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, volume = {521}, unique-id = {33720973}, issn = {0035-8711}, abstract = {In this work, we report the independent discovery and analysis of nine new compact triply eclipsing triple star systems found with the Transiting Exoplanet Survey Satellite (TESS) mission: TICs 47151245, 81525800, 99013269, 229785001, 276162169, 280883908, 294803663, 332521671, and 356324779. Each of these nine systems exhibits distinct third-body eclipses where the third ('tertiary') star occults the inner eclipsing binary (EB), or vice versa. We utilize a photodynamical analysis of the TESS photometry, archival photometric data, TESS eclipse timing variations of the EBs, available archival spectral energy distribution (SED) curves, and, in some cases, newly acquired radial velocity observations, to solve for the parameters of all three stars, as well as most of the orbital elements. From these analyses we find that the outer orbits of all nine systems are viewed nearly edge on (i.e. within ≲4°), and six of the systems are coplanar to within 5°; the others have mutual inclination angles of 20°, 41°, and possibly 179° (i.e. a retrograde outer orbit). The outer orbital periods range from 47.8 to 604 d, with eccentricities spanning 0.004-0.61. The masses of all 18 EB stars are in the range of 0.9-2.6 M⊙ and are mostly situated near the main sequence. By contrast, the masses and radii of the tertiary stars range from 1.4 to 2.8 M⊙ and 1.5 to 13 R⊙, respectively. We make use of the system parameters from these nine systems, plus those from a comparable number of compact triply eclipsing triples published previously, to gain some statistical insight into their properties.}, keywords = {Astrophysics - Solar and Stellar Astrophysics; binaries: eclipsing; binaries (including multiple): close; stars: individual: TIC 47151245; stars: individual: TIC 81525800; stars: individual: TIC 99013269; stars: individual: TIC 229785001}, year = {2023}, eissn = {1365-2966}, pages = {558-584}, orcid-numbers = {Borkovits, Tamás/0000-0002-8806-496X; Mitnyan, Tibor/0000-0001-5803-3938} } @article{MTMT:33637297, title = {New compact hierarchical triple system candidates identified using Gaia DR3}, url = {https://m2.mtmt.hu/api/publication/33637297}, author = {Czavalinga, Donát Róbert and Mitnyan, Tibor and Rappaport, S. A. and Borkovits, Tamás and Gagliano, R. and Omohundro, M. and Kristiansen, M. H. K. and Pál, András}, doi = {10.1051/0004-6361/202245300}, journal-iso = {ASTRON ASTROPHYS}, journal = {ASTRONOMY & ASTROPHYSICS}, volume = {670}, unique-id = {33637297}, issn = {0004-6361}, abstract = {Aims: We introduce a novel way to identify new compact hierarchical triple stars by exploiting the huge potential of Gaia DR3 and also its future data releases. We aim to increase the current number of compact hierarchical triple systems significantly. Methods: We used several eclipsing binary catalogs from different sky surveys that list a total of more than 1 million targets to search for Gaia DR3 non-single-star orbital solutions with periods substantially longer than the eclipsing periods of the binaries. Those solutions in most cases are likely to belong to outer orbits of tertiary stars in those systems. We also attempted to validate some of our best-suited candidates using TESS eclipse timing variations. Results: We find 403 objects with suitable Gaia orbital solutions of which 27 are already known triple systems, leaving 376 newly identified hierarchical triple system candidates in our sample. We find the cumulative probability distribution of the outer orbit eccentricities to be very similar to those found in earlier studies based on observations of the Kepler and OGLE missions. We find measurable nonlinear eclipse timing variations or third-body eclipses in the TESS data for 192 objects which we also consider to be confirmed candidates. Of these, we construct analytical light-travel time effect models for the eclipse timing variations of 22 objects with wellsampled TESS observations. We compare the outer orbital parameters from our solutions with those from the Gaia solutions and find that the most reliable orbital parameter is the orbital period, while the values of the other parameters should be used with caution. Full Table A.1 is only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/670/A75}, keywords = {catalogs; binaries: visual; binaries: close; binaries: eclipsing; binaries: spectroscopic}, year = {2023}, eissn = {1432-0746}, orcid-numbers = {Mitnyan, Tibor/0000-0001-5803-3938; Borkovits, Tamás/0000-0002-8806-496X} }