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G. Maciejewski

Publications and source records attributed to G. Maciejewski.

At least 19 recordsLinked to original sources
arXiv2026

Planet-star interactions with precise transit timing. V. Tidal decay of hot Jupiters through wave breaking

Tidal interactions shape the evolution of close-in giant planets and internal gravity-wave breaking offers an efficient pathway for dynamical-tide dissipation, although its population-wide impact remains poorly constrained. We aim to quantify wave-breaking tidal dissipation for 550 hot Jupiters, accounting for stellar-parameter uncertainties. We also aim to identify the most promising systems for detecting orbital decay through transit timing.\\ Stellar masses, radii, and ages were homogeneously redetermined from spectroscopic and photometric data using an isochrone fitting. For each system, these parameters were propagated through a dedicated \texttt{MESA} model grid to calculate the tidal quality factor, wave-breaking probability, orbital decay rate, transit-timing diagnostics and destruction timescales.\\ Wave breaking is predicted to be largely inactive in pre-intermediate-age main sequence (pre-IAMS) stars. The tidal quality factor for systems undergoing wave breaking peaks between $10^6$ and $10^7$, consistent with population-level inferences. About 43\% of planets, primarily with periods $\lesssim3.5$~d, are expected to inspiral on the main sequence, providing a physical explanation for the observed tendency of hot Jupiters to orbit younger stars. A further 41\% inspiral during post-main-sequence evolution within the stages considered. Systems with periods $\lesssim 1$~d, which could in principle experience the strongest tidal forcing, are unlikely to trigger wave breaking, leaving planets on stable orbits. Conversely, the most rapidly inspiralling systems with high wave-breaking probability might display measurable orbital-period shortening only over multi-decade baselines, eluding immediate detection. In contrast, the demographic imprint of wave breaking on occurrence rates should emerge more readily, with the first signs already visible in current population statistics.

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arXiv2024

Planet-star interactions with precise transit timing. IV. Probing the regime of dynamical tides for GK host stars

Statistical studies show that stars of GK spectral types, with masses below 1.1 Sun mass, are depleted in hot Jupiters. This finding is evidence of tidal orbital decay during the main-sequence lifetime. Theoretical considerations show that in some configurations, the tidal energy dissipation can be boosted by non-linear effects in dynamical tides, which are wave-like responses to tidal forcing. To probe the regime of these dynamical tides in GK stars, we searched for orbital period shortening for 6 selected hot Jupiters in systems with 0.8-1 Sun mass host stars: HATS-18, HIP 65A, TrES-3, WASP-19, WASP-43, and WASP-173A. For the hot Jupiters of our sample, we analysed transit timing data sets based on mid-transit points homogeneously determined from observations performed with the Transiting Exoplanet Survey Satellite and high-quality data available in the literature. For the TrES-3 system, we also used new transit light curves we acquired with ground-based telescopes. The mid-transit times were searched for shortening of orbital periods through statistical testing of quadratic transit ephemerides. Theoretical predictions on the dissipation rate for dynamical tides were calculated under the regimes of internal gravity waves (IGWs) undergoing wave breaking (WB) in stellar centres and weak non-linear (WNL) wave-wave interactions in radiative layers. Stellar parameters of the host stars, such as mass and age, which were used in those computations, were homogeneously redetermined using evolutionary models with the Bayesian inference. We found that transit times follow the refined linear ephemerides for all ultra-hot Jupiters of our sample. Non-detection of orbital decay allowed us to place lower constraints on the tidal dissipation rates in those planet-star systems. In three systems, HATS-18, WASP-19, and WASP-43, we reject a scenario with total dissipation of IGWs. We conclude that...

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arXiv2024

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N VIII. A wide-orbit planetary companion in the hot-Jupiter system HD 118203

The star HD 118203, classified as a K0 subgiant, was known to harbour a transiting hot Jupiter planet on a 6.1-day eccentric orbit. Previous studies also revealed a linear trend in the radial velocity (RV) domain, indicative of a companion on a wide orbit. Such a hierarchical orbital architecture could be helpful in studies of the origins of hot Jupiters. We acquired precise RV measurements over 17 years using the 9.2 m Hobby-Eberly Telescope and the 3.6 m Telescopio Nazionale Galileo. Combining these observations with space-born photometric time series from the Transiting Exoplanet Survey Satellite, we constructed a two-planetary model for the system. Astrometric observations from Hipparcos and Gaia were used to constrain the orbital inclination of the wide-orbit companion and its mass. Numerical simulations were used to investigate the dynamics of the system. The photometric data were searched for additional transit-like flux drops. We found that the additional companion is an 11-Jupiter mass planet orbiting HD 118203 on a 14-year moderately eccentric orbit, constituting a hierarchical planetary system with the hot Jupiter. Both planets were found to be dynamically decoupled mainly due to the general relativistic apsidal precession of the inner planet, marginalising secular interactions. The orbits of both planets might have a relatively low mutual inclination unless the longitudes of the ascending node differ substantially. This configuration favours the coplanar high-eccentricity migration as a path to the present-day orbital configuration. No other transiting planets with radii down to 2 Earth radii and orbital periods less than 100 days were found in the system.

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arXiv2023

Search for Planets in Hot Jupiter Systems with Multi-Sector TESS Photometry. IV. Null Detections in 12 Systems

We present the results of our search for nearby planetary companions of transiting hot Jupiters in 12 planetary systems: HAT-P-24, HAT-P-39, HAT-P-42, HAT-P-50, KELT-2, KELT-15, KELT-17, WASP-23, WASP-63, WASP-76, WASP-79, and WASP-161. Our analysis was based on multi-sector time-series photometry from the Transiting Exoplanet Survey Satellite and precise transit timing data sets. We detected no additional transiting planets down to the 2-4 Earth radii regime. For ten hot Jupiters, no departure from linear transit ephemerides was observed. Whilst we refute long-term variations of the orbital period for WASP-161 b, which were claimed in the literature, we notice a tentative hint of the orbital period shortening for WASP-79 b. In addition, we spot a short-period transit timing variation for KELT-2A b with the characteristics typical of the so-called exomoon corridor. We conclude, however, that further observations are required to confirm these findings.

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arXiv2023

A hot super-Earth planet in the WASP-84 planetary system

Hot Jupiters have been perceived as loners devoid of planetary companions in close orbital proximity. However, recent discoveries based on space-borne precise photometry have revealed that at least some fraction of giant planets coexists with low-mass planets in compact orbital architectures. We report detecting a 1.446-day transit-like signal in the photometric time series acquired with the Transiting Exoplanet Survey Satellite (TESS) for the WASP-84 system, which is known to contain a hot Jupiter on a circular 8.5-day orbit. The planet was validated based on TESS photometry, and its signal was distilled in radial velocity measurements. The joint analysis of photometric and Doppler data resulted in a multi-planetary model of the system. With a mass of $15\, M_{\oplus}$, radius of $2\, R_{\oplus}$, and orbital distance of 0.024 au, the new planet WASP-84 c was classified as a hot super-Earth with the equilibrium temperature of 1300 K. A growing number of companions to hot Jupiters indicates that a non-negligible part of them must have formed under a quiescent scenario such as disc migration or in-situ formation.

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arXiv2023

Search for planets in hot Jupiter systems with multi-sector TESS photometry. III. A study of ten systems enhanced with new ground-based photometry

The loneliness of hot Jupiters supports the high-eccentricity migration as a primary path leading to the formation of systems with those planets stripped of any close-in planetary companions. Here we present the null results of searches for low-mass planets close to hot Jupiters in 10 planetary systems: HAT-P-4, HAT-P-10, HAT-P-12, HAT-P-17, HAT-P-19, HAT-P-32, HAT-P-44, Qatar-6, TrES-4, and WASP-48. We employed multi-sector time-series photometry from the Transiting Exoplanet Survey Satellite enhanced with new ground-based transit light curves to determine the sizes of hypothetical planets that might still avoid being detected. We redetermined transit parameters for the known hot Jupiters using a homogenous approach. We refuted transit timing variations for HAT-P-12 b, claimed recently in the literature. The transit timing data permitted us to place tighter constraints on third bodies in HAT-P-19 and HAT-P-32 systems detected in Doppler measurements. We also study four multi-periodic pulsating variable stars in the field around HAT-P-17.

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arXiv2022

Planet-star interactions with precise transit timing. III. Entering the regime of dynamical tides

Hot Jupiters on extremely short-period orbits are expected to be unstable to tidal dissipation and spiral toward their host stars. That is because they transfer the angular momentum of the orbital motion through tidal dissipation into the stellar interior. Although the magnitude of this phenomenon is related to the physical properties of a specific star-planet system, statistical studies show that tidal dissipation might shape the architecture of hot Jupiter systems during the stellar lifetime on the main sequence. The efficiency of tidal dissipation remains poorly constrained in star-planet systems. Stellar interior models show that the dissipation of dynamical tides in radiation zones could be the dominant mechanism driving planetary orbital decay. These theoretical predictions can be verified with the transit timing method. We acquired new precise transit mid-times for five planets. They were previously identified as the best candidates for which orbital decay might be detected. Analysis of the timing data allowed us to place tighter constraints on the orbital decay rate. No statistically significant changes in their orbital periods were detected for all five hot Jupiters in systems HAT-P-23, KELT-1, KELT-16, WASP-18, and WASP-103. For planets HAT-P-23 b, WASP-18 b, and WASP-103 b, observations show that the mechanism of the dynamical tides dissipation probably does not operate in their host stars, preventing them from rapid orbital decay. This finding aligns with the models of stellar interiors of F-type stars, in which dynamical tides are not fully damped due to convective cores. For KELT-16 b, the span of transit timing data was not long enough to verify the theoretical predictions. KELT-1 b was identified as a potential laboratory for studying the dissipative tidal interactions of inertial waves in a convective layer.

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arXiv2022

Photodynamical analysis of the nearly resonant planetary system WASP-148: Accurate transit-timing variations and mutual orbital inclination

WASP-148 is a recently announced extra-solar system harbouring at least two giant planets. The inner planet transits its host star. The planets travel on eccentric orbits and are near the 4:1 mean-motion resonance, which implies significant mutual gravitational interactions. In particular, this causes transit-timing variations of a few minutes, which were detected based on ground-based photometry. This made WASP-148 one of the few cases where such a phenomenon was detected without space-based photometry. Here, we present a self-consistent model of WASP-148 that takes into account the gravitational interactions between all known bodies in the system. Our analysis simultaneously fits the available radial velocities and transit light curves. In particular, we used the photometry secured by the TESS space telescope and made public after the WASP-148 discovery announcement. The TESS data confirm the transit-timing variations, but only in combination with previously measured transit times. The system parameters we derived agree with those previously reported and have a significantly improved precision, including the mass of the non-transiting planet. We found a significant mutual inclination between the orbital planes of the two planets: I=41.0 +6.2 -7.6 deg based on the modelling of the observations, although we found I=20.8 +/- 4.6 deg when we imposed a constraint on the model enforcing long-term dynamical stability. When a third planet was added to the model - based on a candidate signal in the radial velocity - the mutual inclination between planets b and c changed significantly allowing solutions closer to coplanar. We conclude that more data are needed to establish the true architecture of the system. If the significant mutual inclination is confirmed, WASP-148 would become one of the only few candidate non-coplanar planetary systems. We discuss possible origins for this misalignment.

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arXiv2022

Search for planets in hot Jupiter systems with multi-sector TESS photometry. II. Constraints on planetary companions in 12 systems

Uninterrupted observations from space-borne telescopes provide the photometric precision that is required to detect shallow transits of small planets missed by ground-based surveys. We used data from the Transiting Exoplanet Survey Satellite (TESS) to search for nearby planetary companions in 12 planetary systems with hot Jupiters: HD 2685, Qatar-10, WASP-4, WASP-48, WASP-58, WASP-91, WASP-120, WASP-121, WASP-122, WASP-140, XO-6, and XO-7. We also applied the transit timing method based on homogeneously determined mid-transit times in order to search for non-transiting companions that could gravitationally perturb the already known planets. We found no additional planets in those systems down to the regime of sub-Neptunian globes. This negative result is in line with statistical studies, supporting the high-eccentricity migration as a pathway of the investigated giant planets to the tight orbits observed today.

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arXiv2021

Revisiting TrES-5 b: departure from a linear ephemeris instead of short-period transit timing variation

The orbital motion of the transiting hot Jupiter TrES-5 b was reported to be perturbed by a planetary companion on a nearby orbit. Such compact systems do not frequently occur in nature, and learning their orbital architecture could shed some light on hot Jupiters' formation processes. We acquired fifteen new precise photometric time series for twelve transits of TrES-5 b between June 2019 and October 2020 using 0.9-2.0 m telescopes. The method of precise transit timing was employed to verify the deviation of the planet from the Keplerian motion. Although our results show no detectable short-time variation in the orbital period of TrES-5 b and the existence of the additional nearby planet is not confirmed, the new transits were observed about two minutes earlier than expected. We conclude that the orbital period of the planet could vary in a long timescale. We found that the most likely explanation of the observations is the line-of-sight acceleration of the system's barycentre due to the orbital motion induced by a massive, wide-orbiting companion.

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arXiv2020

A Newtonian model for the WASP-148 exoplanetary system enhanced with TESS and ground-based photometric observations

The WASP-148 planetary system has a rare architecture with a transiting Saturn-mass planet on a tight orbit which is accompanied by a slightly more massive planet on a nearby outer orbit. Using new space-born photometry and ground-based follow-up transit observations and data available in literature, we performed modeling that accounts for gravitational interactions between both planets. Thanks to the new transit timing data for planet b, uncertainties of orbital periods and eccentricities for both planets were reduced relative to previously published values by a factor of 3-4. Variation in transit timing has an amplitude of about 20 minutes and can be easily followed-up with a 1-m class telescopes from the ground. An approximated transit ephemeris, which accounts for gravitational interactions with an accuracy up to 5 minutes, is provided. No signature of transits was found for planet c down to the Neptune-size regime. No other transiting companions were found down to a size of about 2.4 Earth radii for interior orbits. We notice, however, that the regime of terrestrial-size planets still remains unexplored in that system.

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arXiv2020

Planet-star interactions with precise transit timing. II. The radial-velocity tides and a tighter constraint on the orbital decay rate in the WASP-18 system

From its discovery, the WASP-18 system with its massive transiting planet on a tight orbit was identified as a unique laboratory for studies on tidal planet-star interactions. In an analysis of Doppler data, which include five new measurements obtained with the HIRES/Keck-I instrument between 2012 and 2018, we show that the radial velocity signal of the photosphere following the planetary tidal potential can be distilled for the host star. Its amplitude is in agreement with both theoretical predictions of the equilibrium tide approximation and an ellipsoidal modulation observed in an orbital phase curve. Assuming a circular orbit, we refine system parameters using photometric time series from TESS. With a new ground-based photometric observation, we extend the span of transit timing observations to 28 years in order to probe the rate of the orbital period shortening. Since we found no departure from a constant-period model, we conclude that the modified tidal quality parameter of the host star must be greater than 3.9x10^6 with 95% confidence. This result is in line with conclusions drawn from studies of the population of hot Jupiters, predicting that the efficiency of tidal dissipation is 1 or 2 orders of magnitude weaker. As the WASP-18 system is one of the prime candidates for detection of orbital decay, further timing observations are expected to push the boundaries of our knowledge on stellar interiors.

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arXiv2019

CoRoT-18 b: Analysis of high-precision transit light curves with starspot features

When a planet occults a spotty area on a stellar surface, the flux increases and a characteristic feature in a light curve - a bump - is observed. Among the planets detected by the CoRoT-mission CoRoT-18 is especially interesting as it exhibited spot crossings that we have analysed in detail. We used four ground-based observations obtained at a 1.5-m telescope in Spain and the 13 available CoRoT-transits to refine and constrain stellar, planetary and geometrical parameters of the system. We found that the derived physical properties slightly deviate from the previously published values, most likely due to the different treatment of the stellar activity. Following a spot over several transits enabled us to measure the stellar rotation period and the spin-orbit alignment. Our derived values of Prot=5.19 +/- 0.03 d and Lambda=6 +/- 13 deg are in agreement with the literature values that were obtained with other methods. Although we cannot exclude a very old age for CoRoT-18, our observations support the young star hypothesis and, hence, yield constraints on the time-scale of planet formation and migration.

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arXiv2018

Planet-star interactions with precise transit timing. I. The refined orbital decay rate for WASP-12 b and initial constraints for HAT-P-23 b, KELT-1 b, KELT-16 b, WASP-33 b, and WASP-103 b

Theoretical calculations and some indirect observations show that massive exoplanets on tight orbits must decay due to tidal dissipation within their host stars. This orbital evolution could be observationally accessible through precise transit timing over a course of decades. The rate of planetary in-spiralling may not only help us to understand some aspects of evolution of planetary systems, but also can be used as a probe of the stellar internal structure. In this paper we present results of transit timing campaigns organised for a carefully selected sample of hot Jupiter-like planets which were found to be the best candidates for detecting planet-star tidal interactions on the Northern hemisphere. Among them, there is the WASP-12 system which is the best candidate for possessing an in-falling giant exoplanet. Our new observations support the scenario of orbital decay of WASP-12 b and allow us to refine its rate. The derived tidal quality parameter of the host star Q'_{*} = (1.82 +/- 0.32) x 10^5 is in agreement with theoretical predictions for subgiant stars. For the remaining systems - HAT-P-23, KELT-1, KELT-16, WASP-33, and WASP-103 - our transit timing data reveal no deviations from the constant-period models, hence constraints on the individual rates of orbital decay were placed. The tidal quality parameters of host stars in at least 4 systems - HAT-P-23, KELT-1, WASP-33, and WASP-103 - were found to be greater than the value reported for WASP-12. This is in line with the finding that those hosts are main sequence stars, for which efficiency of tidal dissipation is predicted to be relatively weak.

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arXiv2018

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. VI. HD 238914 and TYC 3318-01333-1 - two more Li-rich giants with planets

We present the latest results of our search for planets with HARPS-N at the 3.6 m Telescopio Nazionale Galileo under the Tracking Advanced Planetary Systems project: an in-depth study of the 15 most Li abundant giants from the PennState - Toruń Planet Search sample. Our goals are first, to obtain radial velocities of the most Li-rich giants we identified in our sample to search for possible low-mass substellar companions, and second, to perform an extended spectral analysis to define the evolutionary status of these stars. Methods. This work is based on high-resolution spectra obtained with the Hobby-Eberly Telescope and its High Resolution Spectro- graph, and with the HARPS-N spectrograph at the Telescopio Nazionale Galileo. Two stars, HD 181368 and HD 188214 , were also observed with UVES at the VLT to determine beryllium abundances. We report i) the discovery of two new planetary systems around the Li-rich giant stars: HD 238914 and TYC 3318-01333- 1 (a binary system); ii) reveal a binary Li-rich giant, HD 181368 ; iii) although our current phase coverage is not complete, we suggest the presence of planetary mass companions around TYC 3663-01966-1 and TYC 3105-00152-1 ; iv) we confirm the previous result for BD+48 740 and present updated orbital parameters, and v) we find a lack of a relation between the Li enhancement and the Be abundance for the stars HD 181368 and HD 188214 , for which we acquired blue spectra. We found seven stars with stellar or potential planetary companions among the 15 Li-rich giant stars. The binary star frequency of the Li-rich giants in our sample appears to be normal, but the planet frequency is twice that of the general sample, which suggests a possible connection between hosting a companion and enhanced Li abundance in giant stars. We also found most of the companions orbits to be highly eccentric.

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arXiv2017

UVSat: a concept of an ultraviolet/optical photometric satellite

Time-series photometry from space in the ultraviolet can be presently done with only a few platforms, none of which is able to provide wide-field long-term high-cadence photometry. We present a concept of UVSat, a twin space telescope which will be capable to perform this kind of photometry, filling an observational niche. The satellite will host two telescopes, one for observations in the ultraviolet, the other for observations in the optical band. We also briefly show what science can be done with UVSat.

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arXiv2017

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. V.: A Massive Jupiter orbiting the very low metallicity giant star BD+03 2562 and a possible planet around HD~103485

We present two evolved stars from the TAPAS (Tracking Advanced PlAnetary Systems) with HARPS-N project devoted to RV precision measurements of identified candidates within the PennState - Torun Centre for Astronomy Planet Search. Evolved stars with planets are crucial to understand the dependency of the planet formation mechanism on the mass and metallicity of the parent star and to study star-planet interactions. The paper is based on precise radial velocity (RV) measurements, for HD 103485 we collected 57 epochs over 3317 days with the Hobby-Eberly Telescope and its High Resolution Spectrograph and 18 ultra-precise HARPS-N data over 919 days. For BD+03 2562 we collected 46 epochs of HET data over 3380 days and 19 epochs of HARPS-N data over 919 days. We present the analysis of the data and the search for correlations between the RV signal and stellar activity, stellar rotation and photometric variability. Based on the available data, we interpret the RV variations measured in both stars as Keplerian motion. Both stars have masses close to Solar (1.11 and 1.14), very low metallicities ([Fe/H]=-0.50 and -0.71), and, both have Jupiter planetary mass companions (m sin i=7 and 6.4 Mj), in close to terrestrial orbits (1.4 and 1.3~au), with moderate eccentricities (e=0.34 and 0.2). However, we cannot totally exclude that the signal in the case of HD~103485 is due to rotational modulation of active regions. Based on the current data, we conclude that BD+03 2562 has a bona fide planetary companion while for HD 103485 we cannot totally exclude that the best explanation for the RV signal modulations is not the existence of a planet but stellar activity. If, the interpretation remains that both stars have planetary companions they represent systems orbiting very evolved stars with very low metallicities, a challenge to the conditions required for the formation of massive giant gas planets.

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