arXiv subjects

Maciej Konacki

Publications and source records attributed to Maciej Konacki.

At least 19 recordsLinked to original sources

arXiv2026

UX Men: Detached Eclipsing Binary as a Benchmark Candidate

We present ultra-precise fundamental parameters for the detached eclipsing binary UX Men based on 31 TESS sectors ($\sim$882 d) and radial velocities from HARPS, FEROS, CORALIE, and UCLES. The light curves were detrended for spot-induced variability and modelled independently with JKTEBOP and ALLESFITTER, while radial velocities were extracted via TODCOR and fitted with a Keplerian orbit. Spectral disentangling yielded individual component spectra analysed with iSpec to determine $T_{\rm eff}$ and $\mathrm{[M/H]}$. Multi-band photometry was used to determine the fluxes, flux ratios and ultimately to measure photometric $T_{\rm eff}$. We obtain the masses $M_{\rm A}$ = $1.2300 \pm{0.0012}$ M$_{\odot}$, $M_{\rm B}$ = $1.1946\pm{0.0012}$ M$_{\odot}$ and radii $R_{\rm A}$ = $1.3605\pm{0.0031}$ R$_{\odot}$, $R_{\rm B}$ = $1.2801\pm{0.0069}$ R$_{\odot}$ with sub-percent precision. Uncertainties were found to be dominated by systematic effects coming from (weak) stellar activity. $T_{\rm eff,A}$ = $6302\pm{77}$, $T_{\rm eff,B}$ = $6292\pm65$ \& Metallicity estimates are $[M/H]_{\rm A} = 0.02\pm{0.13}$ dex and $[M/H]_{\rm B}= 0.07\pm{0.10}$ dex. Isochrone fitting yields a consistent age of $τ$ = $2.75\pm{0.13}$ Gyr. The system exhibits a $\sim$ 673-day periodicity in eclipse-timing variations, likely due to stellar activity, with no evidence for a third body. Results are independent of the modelling code used, but without proper treatment of activity-induced systematics the uncertainties would be underestimated. UX Men is a high-precision benchmark binary providing stringent tests of stellar models and a robust calibration source for PLATO. Expanding the sample of well-characterised detached eclipsing binaries will strengthen the empirical foundations for stellar physics and the calibration of future photometric missions

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arXiv2019

An apparently eccentric orbit of the exoplanet WASP-12 b as a radial velocity signature of planetary-induced tides in the host star

Massive exoplanets on extremely tight orbits, such as WASP-12 b, induce equilibrium tides in their host stars. Following the orbital motion of the planet, the tidal fluid flow in the star can be detected with the radial velocity method. Its signature manifests as the second harmonics of the orbital frequency that mimics a non-zero orbital eccentricity. Using the new radial velocity measurements acquired with the HARPS-N spectrograph at the Telescopio Nazionale Galileo and combining them with the literature data, we show that the apparent eccentricity of WASP-12 b's orbit is non-zero at a 5.8 sigma level, and the longitude of periastron of this apparently eccentric orbit is close to 270 degrees. This orbital configuration is compatible with a model composed of a circular orbit and a signature of tides raised in the host star. The radial velocity amplitude of those tides was found to be consistent with the equilibrium tide approximation. The tidal deformation is predicted to produce a flux modulation with an amplitude of 80 ppm which could be detected using space-born facilities.

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arXiv2016

Spectroscopic Survey of Eclipsing Binaries with a Low Cost Échelle Spectrograph -- Scientific Commissioning

We present scientific results obtained with a recently commissioned échelle spectrograph on the 0.5-m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit échelle spectrograph that has a resolution of 21,000 at 5,500 Å. The described setup is fully remotely operated and partly automated. Custom hardware components have been designed to allow both spectroscopic and photometric observations. The setup is controlled via dedicated software. The throughput of the system allows us to obtain spectra with an average SNR of 22 at 6375 Å for a 30-min exposure of a $V=10$ mag target. The stability of the instrument is influenced mainly by the ambient temperature changes. We have obtained radial velocity RMS values for a bright (V = 5.9 mag) spectroscopic binary as good as 0.59 km s$^{-1}$ and 1.34 km s$^{-1}$ for a $V = 10.2$ mag eclipsing binary. Radial velocity measurements have been combined with available photometric light curves. We present models of six eclipsing binary systems, and for previously known targets, we compare our results with those available in the literature. Masses of binary components have been determined with 3% errors for some targets. We confront our results with benchmark values based on measurements from the HARPS and UCLES spectrographs on 4-m class telescopes and find very good agreement. The described setup is very efficient and well suited for a spectroscopic survey. We can now spectroscopically characterize about 300 eclipsing binary stars per year up to 10.2 mag assuming typical weather conditions at SAAO without a single observing trip.

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arXiv2015

Absolute stellar parameters of KIC 09246715 -- a double-giant eclipsing system with a solar-like oscillator

We present our results of a combined analysis of radial velocity and light curves of a double-lined spectroscopic and eclipsing binary KIC 09246715, observed photometrically by the $Kepler$ satellite, and spectroscopically with the OAO-1.88m telescope with the HIgh-Dispertion Echelle Spectrograph (HIDES). The target was claimed to be composed of two red giants, one of which is showing solar-like oscillations. We have found that the mass and radius of the primary are $M_1=2.169\pm0.024$ M$_\odot$ and $R_1=8.47\pm0.13$ R$_\odot$, and of the secondary: $M_2=2.143\pm0.025$ M$_\odot$ and $R_2=8.18\pm0.09$ R$_\odot$, which confirms the double-giant status. Our secondary is the star to which the oscillations were attributed. Results of its previous asteroseismic analysis are in agreement with ours, only significantly less precise, but the subsequent light-curve-based study failed to derive correct mass and radius of our primary. KIC 09246715 is one of the rare cases where asteroseismic parameters of a solar-like oscillator were confirmed by an independent method, and only the third example of a Galactic double-giant eclipsing binary with masses and radii measured with precision below 2%.

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arXiv2010

The PHASES Differential Astrometry Data Archive. I. Measurements and Description

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 sub-arcsecond binary systems to determine precision binary orbits, study the geometries of triple and quadruple star systems, and discover previously unknown faint astrometric companions as small as giant planets. PHASES measurements made with the Palomar Testbed Interferometer (PTI) from 2002 until PTI ceased normal operations in late 2008 are presented. Infrared differential photometry of several PHASES targets were measured with Keck Adaptive Optics and are presented.

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arXiv2010

The PHASES Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary

Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems have been combined with lower precision single-aperture measurements covering a much longer timespan (from eyepiece measurements, speckle interferometry, and adaptive optics) to determine improved visual orbits for 20 binary stars. In some cases, radial velocity observations exist to constrain the full three-dimensional orbit and determine component masses. The visual orbit of one of these binaries---alpha Com (HD 114378)---shows that the system is likely to have eclipses, despite its very long period of 26 years. The next eclipse is predicted to be within a week of 2015 January 24.

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arXiv2010

The PHASES Differential Astrometry Data Archive. III. Limits to Tertiary Companions

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Twenty-one of those systems were observed 10 or more times and show no evidence of additional companions. A new algorithm is presented for identifying astrometric companions and establishing the (companion mass)-(orbital period) combinations that can be excluded from existence with high confidence based on the PHASES observations, and the regions of mass-period phase space being excluded are presented for 21 PHASES binaries.

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arXiv2010

The PHASES Differential Astrometry Data Archive IV: The Triple Star Systems 63 Gem A and HR 2896

(Abridged) Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) are used to constrain the astrometric orbit of the previously known lesssim 2 day subsystem in the triple system 63 Gem A and have detected a previously unknown 2 year Keplerian wobble superimposed on the visual orbit of the much longer period (213 years) binary system HR 2896. The very small astrometric perturbation caused by the inner pair in 63 Gem A stretches the limits of current astrometric capabilities, but PHASES observations are able to constrain the orientation of the orbit. The two bright stars comprising the HR 2896 long period (213 year) system have a combined spectral type of K0III and the newly detected object's mass estimate places it in the regime of being a M dwarf. The motion of the stars are slow enough that their spectral features are always blended, preventing Doppler studies. The PHASES measurements and radial velocities (when available) have been combined with lower precision single-aperture measurements covering a much longer timeframe to improve the characterization of the long period orbits in both binaries. The visual orbits of the short and long period systems are presented for both systems, and used to calculate two possible values of the mutual inclinations between inner and outer orbits of 152 pm 12 degrees or a less likely value of 31 pm 11 degrees for 63 Gem A and 10.2 pm 2.4 degrees or 171.2 pm 2.8 degrees for HR 2896. The first is not coplanar, whereas the second is either nearly coplanar or anti-coplanar.

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arXiv2010

The PHASES Differential Astrometry Data Archive. V. Candidate Substellar Companions to Binary Systems

The Palomar High-precision Astrometric Search for Exoplanet Systems monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Six binaries are presented that show evidence of substellar companions orbiting either the primary or secondary star. Of these six systems, the likelihoods of two of the detected perturbations to represent real objects are considered to be "high confidence", while the remaining four systems are less certain and will require continued observations for confirmation.

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arXiv2010

Orbital and physical parameters of eclipsing binaries from the ASAS catalogue -- II. Two spotted M < 1 M$_\odot$ systems at different evolutionary stages

Aims. We present the results of our detailed spectroscopic and photometric analysis of two previously unknown < 1 M{_\sun} detached eclipsing binaries: ASAS J045304-0700.4 and ASAS J082552-1622.8. Methods. With the HIgh Resolution Echelle Spectrometer (HIRES) on the Keck-I telescope, we obtained spectra of both objects covering large fractions of orbits of the systems. We also obtained V and I band photometry with the 1.0-m Elizabeth telescope of the South African Astronomical Observatory (SAAO). The orbital and physical parameters of the systems were derived with the PHOEBE and JKTEBOP codes. We investigated the evolutionary status of both binaries with several sets of widely-used isochrones. Results. Our modelling indicates that (1) ASAS J045304-0700.4 is an old, metal-poor, active system with component masses of M1 = 0.8452 \pm 0.0056 M$_\odot$, M2 = 0.8390 \pm 0.0056 M$_\odot$ and radii of R1 = 0.848 \pm 0.005 R$_\odot$ and R2 = 0.833 \pm 0.005 R$_\odot$, which places it at the end of the Main Sequence evolution - a stage rarely observed for this type of stars. (2) ASAS J082552-1622.8 is a metal-rich, active binary with component masses of M1 = 0.703 \pm 0.003 M$_\odot$, M2 = 0.687 \pm 0.003 M$_\odot$ and radii of R1 = 0.694(+0.007-0.011) R$_\odot$ and R2 = 0.699(+0.011-0.014) R$_\odot$. Both systems show significant out-of-eclipse variations, probably owing to large, cold spots. we also investigated the influence of a third light in the second system.

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arXiv2009

The Radial Velocity TATOOINE Search for Circumbinary Planets: Planet Detection Limits for a Sample of Double-lined Binary Stars - Initial Results from Keck I/Hires, Shane/CAT/Hamspec and TNG/Sarg Observations

We present preliminary results of the first and on-going radial velocity survey for circumbinary planets. With a novel radial velocity technique employing an iodine absorption cell we achieve an unprecedented RV precision of up to 2 m/s for double-lined binary stars. The high resolution spectra collected with the Keck I/Hires, TNG/Sarg and Shane/CAT/Hamspec telescopes/spectrographs over the years 2003-2008 allow us to derive RVs and compute planet detection limits for ten double-lined binary stars. For this initial sample of targets, we can rule out planets on dynamically stable orbits with masses as small as ~0.3 to 3 MJup for the orbital periods of up to ~5.3 years. Even though the presented sample of stars is too small to make any strong conclusions, it is clear that the search for circumbinary planets is now technique-wise possible and eventually will provide new constraints for the planet formation theories.

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arXiv2008

Precise Astrometry of Visual Binaries with Adaptive Optics. A Way for Finding Exoplanets?

We present the results of our study of astrometric stability of 200-in Hale (Mt. Palomar) and 10-m Keck II (Mauna Kea) telescopes, both with Adaptive Optics (AO) facilities. A group of nearby visual binaries and multiples was observed in near infrared, relative separations and position angles measured. We have also checked the influence of some systematic effects (e.g. atmospherical refraction, varying plate scale factor) on result and precision of astrometric measurements. We conclude that in visual binaries astrometrical observations it is possible to achieve much better precision than 1 miliarcsecond, which in many cases allows detection of the astrometrical signal produced by planetary-mass object.

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arXiv2007

The orbits of the quadruple star system 88 Tau A from PHASES differential astrometry and radial velocity

We have used high precision differential astrometry from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) project and radial velocity measurements covering a time-span of 20 years to determine the orbital parameters of the 88 Tau A system. 88 Tau is a complex hierarchical multiple system comprising a total of six stars; we have studied the brightest 4, consisting of two short-period pairs orbiting each other with an 18-year period. We present the first orbital solution for one of the short-period pairs, and determine the masses of the components and distance to the system to the level of a few percent. In addition, our astrometric measurements allow us to make the first determination of the mutual inclinations of the orbits. We find that the sub-systems are not coplanar.

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arXiv2007

Masses, Luminosities, and Orbital Coplanarities of the mu Orionis Quadruple Star System from PHASES Differential Astrometry

mu Orionis was identified by spectroscopic studies as a quadruple star system. Seventeen high precision differential astrometry measurements of mu Ori have been collected by the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES). These show both the motion of the long period binary orbit and short period perturbations superimposed on that caused by each of the components in the long period system being themselves binaries. The new measurements enable the orientations of the long period binary and short period subsystems to be determined. Recent theoretical work predicts the distribution of relative inclinations between inner and outer orbits of hierarchical systems to peak near 40 and 140 degrees. The degree of coplanarity of this complex system is determined, and the angle between the planes of the A-B and Aa-Ab orbits is found to be 136.7 +/- 8.3 degrees, near the predicted distribution peak at 140 degrees; this result is discussed in the context of the handful of systems with established mutual inclinations. The system distance and masses for each component are obtained from a combined fit of the PHASES astrometry and archival radial velocity observations. The component masses have relative precisions of 5% (component Aa), 15% (Ab), and 1.4% (each of Ba and Bb). The median size of the minor axes of the uncertainty ellipses for the new measurements is 20 micro-arcseconds. Updated orbits for delta Equulei, kappa Pegasi, and V819 Herculis are also presented.

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arXiv2007

Observational Techniques for Detecting Planets in Binary Systems

Searches for planets in close binary systems explore the degree to which stellar multiplicity inhibits or promotes planet formation. There is a degeneracy between planet formation models when only systems with single stars are studied--several mechanisms appear to be able to produce such a final result. This degeneracy is lifted by searching for planets in binary systems; the resulting detections (or evidence of non-existence) of planets in binaries isolates which models may contribute to how planets form in nature. In this chapter, we consider observational efforts to detect planetary companions to binary stars in two types of hierarchical planet-binary configurations: first ``S-type'' planets which orbit just one of the stars, with the binary period being much longer than the planet's; second, ``P-type'' or circumbinary planets, where the planet simultaneously orbits both stars, and the planetary orbital period is much longer than that of the binary. The S-type planet finding techniques are different for binaries that can or cannot be spatially resolved. For wider systems, techniques reviewed include dualstar interferometric differential astrometry and precision radial velocities. Alternatively, unresolved binaries can be studied using modified dualstar "PHASES-style" differential astrometry or a modification of the radial velocity technique for composite spectra. Should a fortunately aligned--but still long period--binary be found, eclipse timing can also reveal the presence of S-type planets. Methods for detecting P-type planets include the composite-spectra variant of the radial velocity technique and eclipse timing.

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arXiv2006

Scientific Results from High-precision Astrometry at the Palomar Testbed Interferometer

A new observing mode for the Palomar Testbed Interferometer was developed in2002-2003 which enables differential astrometry at the level of 20 micro-arcseconds for binary systems with separations of several hundred milli-arcseconds (mas). This phase-referenced mode is the basis of the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES), a search for giant planets orbiting either the primary or secondary star in fifty binary systems. We present the first science results from the PHASES search. The properties of the stars comprising binary systems are determined to high precision. The mutual inclinations of several hierarchical triple star systems have been determined. We will present upper limits constraining the the existence of giant planets in a few of the target systems.

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arXiv2006

Trojan pairs in the HD 128311 and HD 82943 planetary systems?

Two nearby stars, HD 128311 and HD 82943, are believed to host pairs of Jupiter-like planets involved in a strong first order 2:1 mean motion resonance (MMR). In this work we reanalyze available radial velocity (RV) measurements and demonstrate that it is also possible to explain the observed RV variations of the parents stars as being induced by a pair of Trojan planets (i.e., in a 1:1 MMR). We show that these Trojan configurations reside in extended zones of stability in which such systems may easily survive in spite of large masses of the planets, large eccentricities and nonzero mutual inclinations of their orbits. We also show that HD 82943 could harbor a previously unknown third planet about of 0.5 Jupiter masses in 2.1 AU orbit.

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arXiv2005

Orbital configurations and dynamical stability of multi-planet systems around Sun-like stars HD 202206, 14 Her, HD 37124 and HD 108874

We perform a dynamical analysis of the recently published radial velocity (RV) measurements of a few solar type stars which host multiple Jupiter-like planets. In particular, we re-analyze the data for HD 202206, 14 Her, HD 37124 and HD 108874. We derive dynamically stable configurations which reproduce the observed RV signals using our method called GAMP (an acronym of the Genetic Algorithm with MEGNO Penalty). The GAMP relies on the N-body dynamics and makes use of genetic algorithms merged with a stability criterion. For this purpose, we use the maximal Lyapunov exponent computed with the dynamical fast indicator MEGNO. Through a dynamical analysis of the phase-space in a neighborhood of the obtained best-fit solutions, we derive meaningful limits on the parameters of the planets. We demonstrate that GAMP is especially well suited for the analysis of the RV data which only partially cover the longest orbital period and/or correspond to multi-planet configurations involved in low-order mean motion resonances (MMRs). In particular, our analysis reveals a presence of a second Jupiter-like planet in the 14 Her system (14 Her c) involved in a 3:1 or 6:1 MMR with the known companion b. We also show that the dynamics of the HD 202206 system may be qualitatively different when coplanar and mutually-inclined orbits of the companions are considered. We demonstrate that the two outer planets in the HD 37124 system may reside in a close neighborhood of the 5:2 MMR. Finally, we found a clear indication that the HD 108874 system may be very close to, or locked in an exact 4:1 MMR.

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