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Many circumbinary gas giant planets have been recently discovered. The formation mechanism of circumbinary planets on wide orbits is unclear. We investigate the formation of Delorme 1 (AB)b, a |$13 \pm 5 \ \mathrm{ M_J}$| planet, orbiting its host binary at 84 au. The planet is accreting while having an estimated age of 40 Myr, which is unexpected, as this process should have ceased due to the dissipation of the protoplanetary disc. Using the smoothed particle hydrodynamics code seren , we model three formation scenarios for this planet. In Scenario I, the planet forms in situ on a wide orbit in a massive disc (by gravitational instability), in Scenario II closer to the binary in a massive disc (by gravitational instability), and in Scenario III much closer to the binary in a less massive disc (by core accretion). Planets in Scenario I stay at the observed separation and have mass accretion rates consistent with observed value, but their final mass is too high. In Scenario II, the planet reaches the observed separation through outward migration or scattering by the binary, and has mass accretion rate comparable to the observed; however, the planet mass is above the observed value. In Scenario III, the planet's final mass and mass accretion rate are comparable to the observed ones, but the planet's separation is smaller. We conclude that all models may explain some features of the observations but not all of them, raising questions about how gas is accreted on to the planet from its circumplanetary disc, and the presumed age of the system. [ABSTRACT FROM AUTHOR]

We study the evolution of eccentricity and inclination of massive planets in low-density cavities of protoplanetary discs using three-dimensional (3D) simulations. When the planet's orbit is aligned with the equatorial plane of the disc, the eccentricity increases to high values of 0.7–0.9 due to the resonant interaction with the inner parts of the disc. For planets on inclined orbits, the eccentricity increases due to the Kozai–Lidov mechanism, where the disc acts as an external massive body, which perturbs the planet's orbit. At small inclination angles, |${\lesssim}30^\circ$|⁠ , the resonant interaction with the inner disc strongly contributes to the eccentricity growth, while at larger angles, eccentricity growth is mainly due to the Kozai–Lidov mechanism. We conclude that planets inside low-density cavities tend to acquire high eccentricity if favourable conditions give sufficient time for growth. The final value of the planet's eccentricity after the disc dispersal depends on the planet's mass and the properties of the cavity and protoplanetary disc. [ABSTRACT FROM AUTHOR]

We investigate the planetary migration of low-mass planets (⁠|$M_p\in [1,15]\, \mathrm{ M}_{\oplus }$|⁠ , here |$\mathrm{ M}_{\oplus }$| is the Earth mass) in a gaseous disc containing a previously formed gap. We perform high-resolution 3D simulations with the fargo3d code. To create the gap in the surface density of the disc, we use a radial viscosity profile with a bump, which is maintained during the entire simulation time. We find that when the gap is sufficiently deep, the spiral waves excited by the planet trigger the Rossby wave instability, forming cyclonic (underdense) vortices at the edges of the gap. When the planet approaches the gap, it interacts with the vortices, which produce a complex flow structure around the planet. Remarkably, we find a widening of the horseshoe region of the planet produced by the vortex at the outer edge of the gap, which depending on the mass of the planet differs by at least a factor of two with respect to the standard horseshoe width. This inevitably leads to an increase in the co-rotation torque on the planet and produces an efficient trap to halt its inward migration. In some cases, the planet becomes locked in co-rotation with the outer vortex. Under this scenario, our results could explain why low-mass planets do not fall towards the central star within the lifetime of the protoplanetary disc. Lastly, the development of these vortices produces an asymmetric temporal evolution of the gap, which could explain the structures observed in some protoplanetary discs. [ABSTRACT FROM AUTHOR]

We report the discovery of two transiting planets detected by the Transiting Exoplanet Survey Satellite (TESS), TOI-2374 b and TOI-3071 b, orbiting a K5V and an F8V star, respectively, with periods of 4.31 and 1.27 d, respectively. We confirm and characterize these two planets with a variety of ground-based and follow-up observations, including photometry, precise radial velocity monitoring and high-resolution imaging. The planetary and orbital parameters were derived from a joint analysis of the radial velocities and photometric data. We found that the two planets have masses of (57 ± 4) M ⊕ or (0.18 ± 0.01) MJ , and (68 ± 4) M ⊕ or (0.21 ± 0.01) MJ , respectively, and they have radii of (6.8 ± 0.3) R ⊕ or (0.61 ± 0.03) RJ and (7.2 ± 0.5) R ⊕ or (0.64 ± 0.05) RJ , respectively. These parameters correspond to sub-Saturns within the Neptunian desert, both planets being hot and highly irradiated, with T eq ≈ 745 K and T eq ≈ 1812 K, respectively, assuming a Bond albedo of 0.5. TOI-3071 b has the hottest equilibrium temperature of all known planets with masses between 10 and 300  M ⊕ and radii less than 1.5  RJ. By applying gas giant evolution models we found that both planets, especially TOI-3071 b, are very metal-rich. This challenges standard formation models which generally predict lower heavy-element masses for planets with similar characteristics. We studied the evolution of the planets' atmospheres under photoevaporation and concluded that both are stable against evaporation due to their large masses and likely high metallicities in their gaseous envelopes. [ABSTRACT FROM AUTHOR]

Planetary systems in mean motion resonances hold a special place among the planetary population. They allow us to study planet formation in great detail as dissipative processes are thought to have played an important role in their existence. Additionally, planetary masses in bright resonant systems can be independently measured via both radial velocities and transit timing variations. In principle, they also allow us to quickly determine the inclination of all planets in the system since, for the system to be stable, they are likely all in coplanar orbits. To describe the full dynamical state of the system, we also need the stellar obliquity, which provides the orbital alignment of a planet with respect to the spin of its host star and can be measured thanks to the Rossiter–McLaughlin effect. It was recently discovered that HD 110067 harbors a system of six sub-Neptunes in resonant chain orbits. We here analyze an ESPRESSO high-resolution spectroscopic time series of HD 110067 during the transit of planet c. We find the orbit of HD 110067 c to be well aligned, with a sky-projected obliquity of λ =6+24-26 deg. This result indicates that the current architecture of the system was reached through convergent migration without any major disruptive events. Finally, we report transit-timing variation in this system as we find a significant offset of 19 ± 4 min in the center of the transit compared to the published ephemeris. [ABSTRACT FROM AUTHOR]

Context. Detecting protoplanets during their formation stage is an important but elusive goal of modern astronomy. Kinematic detections via the spiral wakes in the gaseous disc are a promising avenue to achieve this goal. Aims. We aim to test the applicability of a commonly used semi-analytical model for planet-induced spiral waves to observations in the low and intermediate planet mass regimes. In contrast to previous works that proposed using the semi-analytical model to interpret observations, in this study we analyse for the first time both the structure of the velocity and density perturbations. Methods. We ran a set of FARGO3D hydrodynamic simulations and compared them with the output of the semi-analytic model in the code WAKEFLOW. We divided the disc into two regions. We used the density and velocity fields from the simulation in the linear region, where density waves are excited. In the non-linear region, where density waves propagate through the disc, we then solved Burgers' equation to obtain the density field, from which we computed the velocity field. Results. We find that the velocity field derived from the analytic theory is discontinuous at the interface between the linear and nonlinear regions. After ~0.2 rp from the planet, the behaviour of the velocity field closely follows that of the density perturbations. In the low mass limit, the analytical model is in qualitative agreement with the simulations, although it underestimates the azimuthal width and the amplitude of the perturbations, predicting a stronger decay but a slower azimuthal advance of the shock fronts. In the intermediate regime, the discrepancy increases, resulting in a different pitch angle between the spirals of the simulations and the analytic model. Conclusions. The implementation of a fitting procedure based on the minimisation of intensity residuals is bound to fail due to the deviation in pitch angle between the analytic model and the simulations. In order to apply this model to observations, it needs to be revisited so that it can also account for higher planet masses. [ABSTRACT FROM AUTHOR]

In circumstellar disks around young stars, the gravitational influence of nascent planets produces telltale patterns in density, temperature, and kinematics. To better understand these signatures, we first performed 3D hydrodynamical simulations of a 0.012 M⊙ disk with a Saturn-mass planet orbiting circularly in-plane at 40 au. We tested four different disk thermodynamic prescriptions (in increasing order of complexity: local isothermality, β cooling, two-temperature radiation hydrodynamics, and three-temperature radiation hydrodynamics), finding that β cooling offers a reasonable approximation for the three-temperature approach when the planet is not massive or luminous enough to substantially alter the background temperature and density structure. Thereafter, using the three-temperature scheme, we relaxed this assumption, simulating a range of different planet masses (Neptune-mass, Saturn-mass, and Jupiter-mass) and accretion luminosities (0 and 10−3L⊙) in the same disk. Our investigation revealed that signatures of disk–planet interaction strengthen with increasing planet mass, with circumplanetary flows becoming prominent in the high-planet-mass regime. Accretion luminosity, which adds pressure support around the planet, was found to weaken the midplane Doppler flip, which is potentially visible in optically thin tracers such as C18O, while strengthening the spiral signature, particularly in upper disk layers sensitive to thicker lines, such as those of 12CO. [ABSTRACT FROM AUTHOR]

Aims. We aim to investigate the nature of the short-term anomaly that appears in the lensing light curve of KMT-2023-BLG-1866. The anomaly was only partly covered due to its short duration of less than a day, coupled with cloudy weather conditions and a restricted nighttime duration. Methods. Considering the intricacy of interpreting partially covered signals, we thoroughly explored all potential degenerate solutions. Through this process, we identified three planetary scenarios that account for the observed anomaly equally well. These scenarios are characterized by the specific planetary parameters: (s, q)inner = [0.9740 ± 0.0083, (2.46 ± 1.07) × 10−5], (s, q)intermediate = [0.9779 ± 0.0017, (1.56 ± 0.25) × 10−5], and (s, q)outer = [0.9894 ± 0.0107, (2.31 ± 1.29) × 10−5], where s and q denote the projected separation (scaled to the Einstein radius) and mass ratio between the planet and its host, respectively. We identify that the ambiguity between the inner and outer solutions stems from the inner-outer degeneracy, while the similarity between the intermediate solution and the others is due to an accidental degeneracy caused by incomplete anomaly coverage. Results. Through Bayesian analysis utilizing the constraints derived from measured lensing observables and blending flux, our estimation indicates that the lens system comprises a very-low-mass planet orbiting an early M-type star situated approximately (6.2–6.5) kpc from Earth in terms of median posterior values for the different solutions. The median mass of the planet host is in the range of (0.48–0.51) M⊙, and that of the planet's mass spans a range of (2.6–4.0) ME, varying across different solutions. The detection of KMT-2023-BLG-1866Lb signifies the extension of the lensing surveys to very-low-mass planets that have been difficult to detect in earlier surveys. [ABSTRACT FROM AUTHOR]

Context. The young T Tauri star PDS 70 has two gas accreting planets sharing one large gap in a pre-transitional disc. Dust continuum emission from PDS 70 c has been detected by Atacama Large Millimeter/submillimeter Array (ALMA) Band 7, considered as the evidence of a circumplanetary disc. However, there has been no detection of the dust emission from the CPD of PDS 70 b. Aims. We constrain the planet mass and the gas accretion rate of the planets by introducing a model of dust evolution in the CPDs and reproducing the detection and non-detection of the dust emission. Methods. We first develop a 1D steady gas disc model of the CPDs reflecting the planet properties. We then calculate the radial distribution of the dust profiles considering the dust evolution in the gas disc and calculate the total flux density of dust thermal emission from the CPDs. Results. We find positive correlations between the flux density of dust emission and three planet properties, the planet mass, gas accretion rate, and their product called 'MMdot'. We then find that the MMdot of PDS 70 c is ≥4 × 10−7MJ2 yr−1, corresponding to the planet mass of ≥5 MJ and the gas accretion rate of ≥2 × 10−8MJ yr−1. This is the first case to succeed in obtaining constraints on planet properties from the flux density of dust continuum emission from a CPD. We also find some loose constraints on the properties of PDS 70 b from the non-detection of its dust emission. Conclusions. We propose possible scenarios for PDS 70 b and c explaining the non-detection respectively detection of the dust emission from their CPDs. The first explanation is that planet c has larger planet mass, larger gas accretion rate, or both than planet b. The other possibility is that the CPD of planet c has a larger amount of dust supply, weaker turbulence, or both than that of planet b. If the dust supply to planet c is larger than b due to its closeness to the outer dust ring, it is also quantitatively consistent with that planet c has weaker Hα line emission than planet b considering the dust extinction effect. [ABSTRACT FROM AUTHOR]

Aims. We investigate whether volcanic exomoons can be detected in thermal wavelength light curves due to their phase variability along their orbit. The method we use is based on the photometric signal variability that volcanic features or hotspots would cause in infrared (IR) wavelengths, when they are inhomogeneously distributed on the surface of a tidally heated exomoon (THEM). Methods. We simulated satellites of various sizes around an isolated planet and modeled the system's variability in two IR wavelengths, taking into account photon shot noise. The moon's periodic signal as it orbits the planet introduces a peak in the frequency space of the system's time-variable flux. We investigated the THEM and system properties that would make a moon stand out in the frequency space of its host's variable flux. Results. The moon's signal can produce a prominent feature in its host's flux periodogram at shorter IR wavelengths for hotspots with temperatures similar to the ones seen on the Jovian moon, Io, while the same moon would not be identifiable in longer IR wavelengths. By comparing observations at two different wavelengths, we are able to disentangle the signal of an exomoon with transiting and non-transiting orbital inclinations from the planet's signal in the frequency domain for system distances up to ~10 pc for Mars-sized exomoons and even further for Earth-sized ones. Conclusions. This method enlarges the parameter space of detectable exomoons around isolated planetary mass objects and directly imaged exoplanets, as it is sensitive to Io- to Earth-sized exomoons with hot volcanic features for a wide range of non-transiting orbital inclinations. Exomoon transits and the detection of outgassed volcanic molecules can subsequently confirm a putative detection. [ABSTRACT FROM AUTHOR]

One of the main goals of the NASA Transiting Exoplanet Survey Satellite (TESS) mission is the discovery of Earth-like planets around nearby M-dwarf stars. We present the discovery and validation of three new short-period Earth-sized planets orbiting nearby M dwarfs: TOI-5720 b, TOI-6008 b, and TOI-6086 b. We combined TESS data, ground-based multicolor light curves, ground-based optical and near-infrared spectroscopy, and Subaru/IRD radial velocity data to validate the planetary candidates and constrain the physical parameters of the systems. In addition, we used archival images, high-resolution imaging, and statistical validation techniques to support the planetary validation. TOI-5720 b is an Earth-sized planet with a radius of Rp = 1.09 ± 0.07 R⊕. It orbits a nearby (36 pc) M 2.5 host with an orbital period of P = 1.4344555 ± 0.0000036 days. It has an equilibrium temperature of Teq = 708 ± 19 K (assuming a null albedo) and an incident flux of Sp = 41.7 ± 4.5 S⊕. TOI-6008 b is a short-period planet of P = 0.8574347 ± 0.0000424 day. It has a radius of Rp = 1.03 ± 0.05 R⊕, an equilibrium temperature of Teq = 707 ± 19 K, and an incident flux of Sp = 41.5 ± 4.5 S⊕. The host star (TOI-6008) is a nearby (23 pc) M 5 with an effective temperature of Teff = 3075 ± 75 K. Based on the radial velocity measurements collected with Subaru/IRD, we set a 3σ upper limit of Mp < 4 M⊕, thus ruling out a star or brown dwarf as the transiting companion. TOI-6086 b orbits its nearby (32 pc) M 3 host star (Teff = 3200 ± 75 K) every 1.3888725 ± 0.0000827 days and has a radius of Rp = 1.18 ± 0.07 R⊕, an equilibrium temperature of Teq = 634 ± 16 K, and an incident flux of Sp = 26.8 ± 2.7 S⊕. Additional high-precision radial velocity measurements are needed to derive the planetary masses and bulk densities and to search for additional planets in the systems. Moreover, short-period Earth-sized planets orbiting around nearby M dwarfs are suitable targets for an atmospheric characterization with the James Webb Space Telescope through transmission and emission spectroscopy and phase-curve photometry. [ABSTRACT FROM AUTHOR]

The architecture and masses of planetary systems in the habitable zone could be strongly influenced by the presence of outer giant planets. Here, we investigate the impact of outer giants on terrestrial planet formation, under the assumption that the final assembly of the planetary system is set by a giant impact phase. Utilizing a state-of-the-art N-body simulation software, GENGA, we interpret how the late stage of terrestrial planet formation contributes to diversity among planetary systems. We designed two global model setups: 1) we placed a gas giant on the outer side of planetesimals and embryo disk and 2) we only included planetesimals and embryos, but no giant. For the model including the outer giant, we studied the effect of different giant initial masses in the range of 1.0–3.0 Jupiter masses, as well as a range of orbital radii from 2.0–5.8 AU. We also studied the influence of different initial positions of planetesimals and embryos on the results. Our N-body simulation time is approximately 50 Myr. The results show that the existence of an outer giant will promote the interaction between planetesimals and embryos, making the orbits of the formed terrestrial planets more compact. However, placing the giant planet too close to the planetesimals and embryo disk suppresses the formation of massive rocky planets. In addition, under the classical theory, where planetary embryos and planetesimals collide to form terrestrial planets, our results show that the presence of a giant planet actually decreases the gap complexity of the inner planetary system. [ABSTRACT FROM AUTHOR]

We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837 b, with an orbital period of ∼8.32 d. Utilizing data from the Transiting Exoplanet Survey Satellite and ground-based observations, we determine a planetary radius of |$0.818_{-0.024}^{+0.034}$| R J for TOI-837 b. Through detailed High Accuracy Radial Velocity Planet Searcher spectroscopic time series analysis, we derive a Doppler semi-amplitude of |$34.7_{-5.6}^{+5.3}$| |${\rm m\, s^{-1}}$|⁠ , corresponding to a planetary mass of |$0.379_{-0.061}^{+0.058}$| M J. The derived planetary properties suggest a substantial core of approximately 70 M⊕, constituting about 60 per cent of the planet's total mass. This finding poses a significant challenge to existing theoretical models of core formation. We propose that future atmospheric observations with JWST could provide insights into resolving ambiguities of TOI-837 b, offering new perspectives on its composition, formation, and evolution. [ABSTRACT FROM AUTHOR]

This paper examines the dynamic evolution of the compact three-planet system Kepler-51. Possible resonant states of the system are analyzed and a search for potential chains of mean motion resonances is carried out. Using the Posidonius software package the dynamic evolution of the system is studied over a time interval of 100 Myr, taking into account tidal interaction. Also, for various initial values of eccentricities, inclinations, arguments of periapsis and longitudes of the ascending nodes of orbits, modeling of the dynamic evolution of the planetary system is carried out within the framework of the semi-analytical theory of motion. It is shown that the compact planetary system Kepler-51 is not resonant. Under initial conditions corresponding to the masses and elements of the planets' orbits, determined from observations taking into account their errors, the evolution of the system is stable and regular over the studied interval of 100 Myr. [ABSTRACT FROM AUTHOR]

L 98-59b is a transiting exoplanet with radius |${0.85^{+0.061}_{-0.047}}$| R ⊕ and orbital period |${2.2531136^{+1.2e-06}_{-1.5e-06}}$| d. In 2021, a Doppler detection of  L 98-59b was announced, with radial velocity (RV) semi-amplitude |$K_{\rm b}=0.46^{+0.20}_{-0.17}$| |$\textrm {m}\, \textrm {s}^{-1}$| inferred from 164 High Accuracy Radial velocity Planet Searcher and 66 Échelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observation RVs. This translated into a mass |$M_{\rm b}=0.40^{+0.16}_{-0.15}$| M ⊕, or half the mass of Venus, making  L 98-59b then (by far) the lowest mass planet with a putative RV detection. To illuminate the difficulties in securely detecting <1  |$\textrm {m}\, \textrm {s}^{-1}$|  signals, we argue here that the published RV detection of  L 98-59b is not supported by sufficient statistical evidence. We show, under the published modelling assumptions, that Bayesian model comparison (BMC) suggests an |$\sim 50~{{\ \rm per\ cent}}$| false-detection probability. We also often infer ∼40  |$\textrm {cm}\, \textrm {s}^{-1}$| semi-amplitudes for Keplerians with periods not corresponding to any known planet; importantly, though, BMC rejects all these 'detections'. By implementing a more sophisticated stellar activity model and more realistic parameter priors, we infer a mass M b = 0.47 ± 0.14 M ⊕ from semi-amplitude K b = 0.56 ± 0.16  |$\textrm {m}\, \textrm {s}^{-1}$|⁠ , with BMC now indicating substantial yet still not decisive evidence for the detection. Definitive detection and characterization may require many additional RVs, alongside careful modelling and stringent statistical analysis. Our case study has implications for current extreme-precision RV campaigns and the longer term quest to discover the first Earth-twins. [ABSTRACT FROM AUTHOR]

Atacama Large Millimetre/submillimetre Array (ALMA) observations of the thermal emission from protoplanetary disc dust have revealed a wealth of substructures that could evidence embedded planets, but planet-driven spirals, one of the more compelling lines of evidence, remain relatively rare. Existing works have focused on detecting these spirals using methods that operate in image space. Here, we explore the planet detection capabilities of fitting planet-driven spirals to disc observations directly in visibility space. We test our method on synthetic ALMA observations of planet-containing model discs for a range of disc/observational parameters, finding it significantly outperforms image residuals in identifying spirals in these observations and is able to identify spirals in regions of the parameter space in which no gaps are detected. These tests suggest that a visibility-space fitting approach warrants further investigation and may be able to find planet-driven spirals in observations that have not yet been found with existing approaches. We also test our method on six discs in the Taurus molecular cloud observed with ALMA at 1.33 mm, but find no evidence for planet-driven spirals. We find that the minimum planet masses necessary to drive detectable spirals range from ≈0.03 to |$0.5 \, M_{\text{Jup}}$| over orbital radii of 10–100 au, with planet masses below these thresholds potentially hiding in such disc observations. Conversely, we suggest that planets ≳0.5–1  M Jup can likely be ruled out over orbital radii of ≈20– |$60 \, \text{au}$| on the grounds that we would have detected them if they were present. [ABSTRACT FROM AUTHOR]

In the past decade, ALMA observations of protoplanetary disks revealed various substructures including gaps and rings. Their origin of substructures may be probed through statistical studies of their physical properties. We present the analyses of archival ALMA Band 6 continuum data of 43 disks (39 Class II and four Herbig Ae) in the Taurus–Auriga region. We employ a novel 2D super-resolution imaging technique based on sparse modeling to obtain images with high fidelity and spatial resolution. As a result, we have obtained images with spatial resolutions comparable to a few au (⁠|${0_{.}^{\prime\prime}02}$| – |${0_{.}^{\prime\prime}1}$|⁠), which is two to three times better than conventional CLEAN methods. All dust disks are spatially resolved, with the radii ranging from 8 to 238 au with a median radius of 45 au. Half of the disks harbor clear gap structures, the radial locations of which show a bimodal distribution with peaks at ≲20 au and ≳30 au. We also see structures indicating weak gaps at all the radii in the disk. We find that the widths of these gaps increase with their depths, which is consistent with the model of planet–disk interactions. The inferred planet mass–orbital radius distribution indicates that the planet distribution is analogous to our solar system. However, planets with Neptune mass or lower may exist in all the radii. [ABSTRACT FROM AUTHOR]

Exoplanets in their infancy are ideal targets to probe the formation and evolution history of planetary systems, including the planet migration and atmospheric evolution and dissipation. In this paper, we present spectroscopic observations and analyses of two planetary transits of K2-33b, which is known to be one of the youngest transiting planets (age ≈ 8–11 Myr) around a pre-main-sequence M-type star. Analysing K2-33's near-infrared spectra obtained by the IRD instrument on Subaru, we investigate the spin-orbit angle and transit-induced excess absorption for K2-33b. We attempt both classical modelling of the Rossiter–McLaughlin (RM) effect and Doppler-shadow analyses for the measurements of the projected stellar obliquity, finding a low angle of |$\lambda =-6_{-58}^{+61}$| deg (for RM analysis) and |$\lambda =-10_{-24}^{+22}$| deg (for Doppler-shadow analysis). In the modelling of the RM effect, we allow the planet-to-star radius ratio to float freely to take into account the possible smaller radius in the near infrared, but the constraint we obtain (⁠|$R_p/R_s=0.037_{-0.017}^{+0.013}$|⁠) is inconclusive due to the low radial-velocity precision. Comparison spectra of K2-33 of the 1083 nm triplet of metastable ortho-He I obtained in and out of the 2021 transit reveal excess absorption that could be due to an escaping He-rich atmosphere. Under certain conditions on planet mass and stellar XUV emission, the implied escape rate is sufficient to remove an Earth-mass H/He in ∼1 Gyr, transforming this object from a Neptune to a super-Earth. [ABSTRACT FROM AUTHOR]

High-contrast eclipsing binaries with low mass M-dwarf secondaries are precise benchmark stars to build empirical mass–radius relationships for fully convective low-mass (⁠|$\rm M_{\star } \lt 0.35\, M_{\odot }$|⁠) dwarf stars. The contributed light of the M-dwarf in such binaries is usually much less than one per cent at optical wavelengths. This enables the detection of circumbinary planets from precise radial velocity measurements. High-resolution cross-correlation techniques are typically used to detect exoplanet atmospheres. One key aspect of these techniques is the post-processing, which includes the removal of telluric and spectral lines of the host star. We introduce the application of such techniques to optical high-resolution spectra of the circumbinary planet-host TOI-1338/BEBOP-1, turning it effectively into a double-lined eclipsing binary. By using simulations, we further explore the impact of post-processing techniques for high-contrast systems. We detect the M-dwarf secondary with a significance of 11σ and measure absolute dynamical masses for both components. Compared to previous model-dependent mass measurements, we obtain a four times better precision. We further find that the post-processing results in negligible systematic impact on the radial velocity precision for TOI-1338/BEBOP-1 with more than |$96.6\,$|  per cent (1σ) of the M-dwarf's signal being conserved. We show that these methods can be used to robustly measure dynamical masses of high-contrast single-lined binaries providing important benchmark stars for stellar evolution particularly near the bottom of the main sequence. We also demonstrate how to retrieve the phase curve of an exoplanet with high-resolution spectroscopy using our data. [ABSTRACT FROM AUTHOR]

Despite the thousands of planets in orbit around stars known to date, the mechanisms of planetary formation, migration, and atmospheric loss remain unresolved. In this work, we confirm the planetary nature of a young Saturn-size planet transiting a solar-type star every 8.03 d, TOI-1135 b. The age of the parent star is estimated to be in the interval of 125-1000 Myr based on various activity and age indicators, including its stellar rotation period of 5.13 ± 0.27 days and the intensity of photospheric lithium. We obtained follow-up photometry and spectroscopy, including precise radial velocity measurements using the CARMENES spectrograph, which together with the TESS data allowed us to fully characterise the parent star and its planet. As expected for its youth, the star is rather active and shows strong photometric and spectroscopic variability correlating with its rotation period. We modelled the stellar variability using Gaussian process regression. We measured the planetary radius at 9.02 ± 0.23 R⊕ (0.81 ± 0.02 RJup) and determined a 3σ upper limit of < 51.4 M⊕ (< 0.16 MJup) on the planetary mass by adopting a circular orbit. Our results indicate that TOI-1135 b is an inflated planet less massive than Saturn or Jupiter but with a similar radius, which could be in the process of losing its atmosphere by photoevaporation. This new young planet occupies a region of the mass-radius diagram where older planets are scarse, and it could be very helpful to understanding the lower frequency of planets with sizes between Neptune and Saturn. [ABSTRACT FROM AUTHOR]

We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K–M binary system. Analysis of its spectra and rotation period reveal the star to be young, with an age of 200−200+400 Myr. TOI-8l5b has a 11.2-day period and a radius of 2.94 ± 0.05 R⊕ with transits observed by TESS, CHEOPS, ASTEP, and LCOGT. The outer planet, TOI-8l5c, has a radius of 2.62 ± 0.10 R⊕, based on observations of three nonconsecutive transits with TESS; targeted CHEOPS photometry and radial velocity follow-up with ESPRESSO were required to confirm the 35-day period. ESPRESSO confirmed the planetary nature of both planets and measured masses of 7.6 ± 1.5 M⊕ (ρP = 1.64−0.31+0.33 g cm−3) and 23.5 ± 2.4 M⊕ (ρP = 7.2−1.0+1.1 g cm−3), respectively. Thus, the planets have very different masses, which is unusual for compact multi-planet systems. Moreover, our statistical analysis of mini-Neptunes orbiting FGK stars suggests that weakly irradiated planets tend to have higher bulk densities compared to those undergoing strong irradiation. This could be ascribed to their cooler atmospheres, which are more compressed and denser. Internal structure modeling of TOI-815b suggests it likely has a H-He atmosphere that constitutes a few percent of the total planet mass, or higher if the planet is assumed to have no water. In contrast, the measured mass and radius of TOI-815c can be explained without invoking any atmosphere, challenging planetary formation theories. Finally, we infer from our measurements that the star is viewed close to pole-on, which implies a spin-orbit misalignment at the 3σ level. This emphasizes the peculiarity of the system's orbital architecture, and probably hints at an eventful dynamical history. [ABSTRACT FROM AUTHOR]

Aims. Light curves of microlensing events occasionally deviate from the smooth and symmetric form of a single-lens single-source event. While most of these anomalous events can be accounted for by employing a binary-lens single-source (2L 1S) or a single-lens binary-source (1L2S) framework, it is established that a small fraction of events remain unexplained by either of these interpretations. We carried out a project in which data collected by high-cadence microlensing surveys were reinvestigated with the aim of uncovering the nature of anomalous lensing events with no proposed 2L 1S or 1L 2S models. Methods. From the project we found that the anomaly appearing in the lensing event OGLE-2023-BLG-0836 cannot be explained by the usual interpretations, and we conducted a comprehensive analysis of the event. From thorough modeling of the light curve under sophisticated lens-system configurations, we arrived at the conclusion that a triple-mass lens system is imperative to account for the anomalous features observed in the lensing light curve. Results. From the Bayesian analysis using the measured observables of the event timescale and angular Einstein radius, we determined that the least massive component of the lens has a planetary mass of 4.36−2.18+2.35MJ. This planet orbits within a stellar binary system composed of two stars with masses 0.71−0.36+0.38M⊙ and 0.56−0.28+0.30M⊙. This lensing event signifies the sixth occurrence of a planetary microlensing system in which a planet belongs to a stellar binary system. [ABSTRACT FROM AUTHOR]

Current methods to characterize embedded planets in protoplanetary disc observations are severely limited either in their ability to fully account for the observed complex physics or in their computational and time costs. To address this shortcoming, we developed DBNets: a deep learning tool, based on convolutional neural networks, that analyses substructures observed in the dust continuum emission of protoplanetary discs to quickly infer the mass of allegedly embedded planets. We focussed on developing a method to reliably quantify not only the planet mass, but also the associated uncertainty introduced by our modelling and adopted techniques. Our tests gave promising results achieving an 87% reduction of the log Mp mean squared error with respect to an analytical formula fitted on the same data (DBNets metrics: lmse 0.016, r2-score 97%). With the goal of providing the final user of DBNets with all the tools needed to interpret their measurements and decide on their significance, we extensively tested our tool on out-of-distribution data. We found that DBNets can identify inputs strongly outside its training scope returning an uncertainty above a specific threshold and we thus provided a rejection criterion that helps determine the significance of the results obtained. Additionally, we outlined some limitations of our tool: it can be reliably applied only on discs observed with inclinations below approximately 60°, in the optically thin regime, with a resolution ~8 times better than the gap radial location and with a signal-to-noise ratio higher than approximately ten. Finally, we applied DBNets to 33 actual observations of protoplanetary discs measuring the mass of 48 proposed planets and comparing our results with the available literature. We confirmed that most of the observed gaps imply planets in the sub-Jupiter regime. [ABSTRACT FROM AUTHOR]

The number of discovered exoplanets now exceeds 5500 allowing statistical analyses of planetary systems. Multi-planet systems are mini-laboratories of planet formation and evolution, and analysing their system architectures can help us to constrain the physics of these processes. Recent works have found evidence of significant intrasystem uniformity in planet properties such as radius, mass, and orbital spacing, collectively termed 'peas in a pod' trends. In particular, correlations in radius and mass have been interpreted as implying uniformity in planet bulk density and composition within a system. However, the samples used to assess trends in mass tend to be small and biased. In this paper, we re-evaluate correlations in planet properties in a large sample of systems with at least two planets for which mass and radius have been directly measured, and therefore bulk density can be calculated. Our sample was assembled using the most up-to-date exoplanet catalogue data, and we compute the relevant statistics while using a procedure to 'weight' the data points according to measurement precision. We find a moderate correlation in radius and a weak correlation in the densities of adjacent planets. However, masses of neighbouring planets show no overall correlation in our main sample and a weak correlation among pairs of planets similar in size or pairs restricted to Mp<100 M⊕, Rp<10 R⊕. Similarly, we show that the intrasystem dispersion in radius is typically less than that in mass and density. We identify ranges in stellar host properties that correlate with stronger uniformity in pairs of adjacent planets: low Teff for planet masses, and low metallicity and old age for planet densities. Furthermore, we explore whether peas in a pod trends extend into planet compositions or interior structures. For small neighbouring planets with similar radii, we show that their masses and interior structures are often disparate, indicating that even within the same system, similarity in radii is not necessarily a good proxy for similarity in composition or the physical nature of the planets. [ABSTRACT FROM AUTHOR]

This study focuses on a marine two-stage tandem hybrid planetary system. Natural frequencies and vibration modes are determined using a translational–torsional coupled dynamic model. Based on the motion characteristics of the transmission system, free vibration is categorized into three typical modes. The parameter sensitivity of natural frequencies is computed, and the effects of structural parameters such as unequally spaced planet, mesh stiffness, planet mass and rotational inertia on the natural frequencies are analyzed. Utilizing the coupling factor, the mode transition criterion for the natural frequencies response to parameters is formulated. The results demonstrate that the vibration modes of the two-stage tandem hybrid planetary system can be classified as the fixed-axis train vibration mode, the differential train vibration mode, and the coupled vibration mode. Unequally spaced planet primarily disrupts vibration modes without significantly affecting natural frequencies. In contrast, the effects of mesh stiffness, planet mass and rotational inertia on the modes are opposite to those of unequally spaced planets. The validity of the parameter sensitivity and mode transition criterion is substantiated through illustrative examples. [ABSTRACT FROM AUTHOR]

The atmospheres of small, close-in exoplanets are vulnerable to rapid mass loss during protoplanetary disc dispersal via a process referred to as 'boil-off', in which confining pressure from the local gas disc reduces, inducing atmospheric loss and contraction. We construct self-consistent models of planet evolution during gaseous core accretion and boil-off. As the surrounding disc gas dissipates, we find that planets lose mass via subsonic breeze outflows which allow causal contact to exist between disc and planet. Planets initially accrete of order |$\sim 10~{{\ \rm per\ cent}}$| in atmospheric mass, however, boil-off can remove |$\gtrsim 90~{{\ \rm per\ cent}}$| of this mass during disc dispersal. We show that a planet's final atmospheric mass fraction is strongly dictated by the ratio of cooling time-scale to disc dispersal time-scale, as well as the planet's core mass and equilibrium temperature. With contributions from core cooling and radioactivity, we show that core luminosity eventually leads to the transition from boil-off to core-powered mass loss. We find that smaller mass planets closest to their host star may have their atmospheres completely stripped through a combination of boil-off and core-powered mass loss during disc dispersal, implying the existence of a population-level radius gap emerging as the disc disperses. We additionally consider the transition from boil-off/core-powered mass loss to X-ray and extreme ultraviolet (XUV) photoevaporation by considering the penetration of stellar XUV photons below the planet's sonic surface. Finally, we show that planets may open gaps in their protoplanetary discs during the late stages of boil-off, which may enhance mass-loss rates. [ABSTRACT FROM AUTHOR]

Featured Application: The microchip laser and its driver control system designed in this study possess the characteristics of being lightweight, compact, and low power consumption. It serves as a fitting candidate for planetary mass spectrometry missions, particularly as a micro-focusing excitation light source for Time-of-Flight (TOF) mass spectrometers. The output laser wavelength is 1064 nm, with pulse duration as low as 410 ps, a continuously adjustable frequency range from 100 to 1000 Hz, a minimum focal spot size of 15 μm, and a single pulse energy reaching up to 16.8 μJ. Additionally, the overall weight is only 106 g. This microchip laser allows for adjustable focal length, spot size, and laser power output, making it versatile for tasks such as compositional analysis and in-situ dating in deep space exploration. Additionally, it can serve as a portable device for mineral exploration and non-destructive testing, presenting extensive application prospects in the field of mass spectrometry analysis. To fulfill the requisites of planetary mass spectrometry applications, this paper introduces the creation of a miniaturized, low-power passive Q-switched microchip laser system. The entire system, inclusive of the laser and all electronic components, weighs 106 g, with power consumption below 3 W. The laser output exhibits a pulse duration of 410 ps, accompanied by a single pulse energy of 16.8 μJ. Augmented by the optical focusing system, the system attains a focal spot size of approximately 15 μm and laser irradiance of up to 22 GW/cm2. The driving control system facilitates versatile regulation of parameters such as output current amplitude, pulse duration, and frequency, thereby modulating the laser output frequency and duty cycle. The microchip laser fully meets the power requirements for exciting plasma from planetary rocks and soil. [ABSTRACT FROM AUTHOR]

In this work, we present the results from a study using the Giant Meterwave Radio Telescope (GMRT) to search for radio emission from planets around three evolved stars namely α Tau, β UMi, and β Gem. Both α Tau and β UMi host massive ∼ 6 MJ mass planets at about ∼1.4 au from the central star, while β Gem is host to a 2.9 MJ mass planet at 1.7 au from the host star. We observe α Tau and β UMi at two upgraded GMRT bands: band 3 (250–500 MHz) and band 4 (550–900 MHz). We also analysed the archival observations from β Gem at 150 MHz from GMRT. We did not detect any radio signals from these systems. At 400 MHz, the 3σ upper limit is 87 μ Jy beam−1 for α Tau b and 77.4 μ Jy beam−1 for β UMi b. From our observations at 650 MHz, we place a 3σ upper limit of 28.2 μ Jy beam−1 for α Tau b and 33.6 μ Jy beam−1 for β UMi b. For β Gem b, at 150 MHz, we place an upper limit of 2.5 mJy. At 400 and 650 MHz, our observations are the deepest radio images for any exoplanetary system. [ABSTRACT FROM AUTHOR]

We report precise radial velocity (RV) observations of HD 212657 (= K2-167), a star shown by K2 to host a transiting sub-Neptune-sized planet in a 10 d orbit. Using Transiting Exoplanet Survey Satellite (TESS) photometry, we refined the planet parameters, especially the orbital period. We collected 74 precise RVs with the HARPS-N spectrograph between August 2015 and October 2016. Although this planet was first found to transit in 2015 and validated in 2018, excess RV scatter originally limited mass measurements. Here, we measure a mass by taking advantage of reductions in scatter from updates to the HARPS-N Data Reduction System (2.3.5) and our new activity mitigation method called CCF Activity Linear Model (CALM), which uses activity-induced line shape changes in the spectra without requiring timing information. Using the CALM framework, we performed a joint fit with RVs and transits using exofast v2 and find Mp  = |$6.3_{-1.4}^{+1.4}$|   |$\, M_{\hbox{$\oplus $}}$| and Rp  = |$2.33^{+0.17}_{-0.15}$|   |$\, R_{\hbox{$\oplus $}}$|⁠ , which places K2-167 b at the upper edge of the radius valley. We also find hints of a secondary companion at a ∼22 d period, but confirmation requires additional RVs. Although characterizing lower mass planets like K2-167 b is often impeded by stellar variability, these systems especially help probe the formation physics (i.e. photoevaporation, core-powered mass-loss) of the radius valley. In the future, CALM or similar techniques could be widely applied to FGK-type stars, help characterize a population of exoplanets surrounding the radius valley, and further our understanding of their formation. [ABSTRACT FROM AUTHOR]

The MAss Spectrometer for Planetary EXploration (MASPEX) is a high-mass-resolution, high-sensitivity, multi-bounce time-of-flight mass spectrometer (MBTOF) capable of measuring minor species with abundances of sub-parts-per-million in Europa's sputter-produced and radiolytically modified exosphere and in its oceanic plumes. The goal of the MASPEX-Europa investigation is to determine, through in-situ measurement of the exosphere and plume composition, whether the conditions for habitability exist or have existed on Europa. As conventionally defined, based on our knowledge of Earth life, the three fundamental conditions for habitability are: (1) the presence of liquid water; (2) the presence of organic compounds and the biogenic elements CHNOPS; and (3) a source of energy available for metabolic processes, which for Europa will most probably be chemosynthetic rather than photosynthetic. Condition (1) is already established by previous indirect (magnetic field) measurements, while MASPEX will contribute directly to the evaluation of condition (2) through highly specific compositional measurements in the Europan exosphere and plumes. The composition measurements will also contribute to the test of condition (3) through disequilibrium states of chemical reactions. Thus, the primary goal of MASPEX for Europa Clipper is to assess the habitability of Europa and specifically of its interior ocean. MASPEX has been developed successfully, and its calibration has demonstrated that it meets its specified requirements for sensitivity, dynamic range, and mass resolution. This paper reports the development of the MASPEX scientific investigation, the instrument, its performance, and calibration. [ABSTRACT FROM AUTHOR]

We conduct gas and dust hydrodynamical simulations of protoplanetary discs with one and two embedded planets to determine the impact that a second planet located further out in the disc has on the potential for subsequent planet formation in the region locally exterior to the inner planet. We show how the presence of a second planet has a strong influence on the collection of solid material near the inner planet, particularly when the outer planet is massive enough to generate a maximum in the disc's pressure profile. This effect in general acts to reduce the amount of material that can collect in a pressure bump generated by the inner planet. When viewing the inner pressure bump as a location for potential subsequent planet formation of a third planet, we therefore expect that the mass of such a planet will be smaller than it would be in the case without the outer planet, resulting in a small planet being sandwiched between its neighbours – this is in contrast to the expected trend of increasing planet mass with radial distance from the host star. We show that several planetary systems have been observed that do not show this trend but instead have a smaller planet sandwiched in between two more massive planets. We present the idea that such an architecture could be the result of the subsequent formation of a middle planet after its two neighbours formed at some earlier stage. [ABSTRACT FROM AUTHOR]

The properties of the planetary system TOI-784, in which an earth-like planet orbits a low-activity star of solar type, are examined. Archived V-band measurements of the brightness of TOI-784 in the ASAS 4 data base do not yield reliable indications about the variability of the brightness owing to rotation or about the cyclical long-term variability of this object. A possible estimate of the magnitude of the rotation period of the star is Prot/sini = 41.7 ± 11.4 days. The age of the system according to the empirical gyrochronological relations equals 7.8±3.4 billion years. The average value of the atmospheric activity parameter logR′HK = – 4.99 which corresponds to the level of low-activity stars with analogous (B-V) color index is found and is close to that of the sun. The radius of the planet TOI-784 b is equal to 1.93 R⊕, its mass is 9.67 M⊕, and its average density is 7.4 g/cm3 (the planet is rocky). An estimate of the loss of matter from the atmosphere of the planet TOI-784 b was obtained from an approximate formula corresponding to a model of loss by the atmosphere with a limit on energy. Calculations have shown that the rate of loss of matter by the atmosphere of the planet is 4.7 ⋅ 108 g/s. The relatively low rate of loss of matter by the planet's atmosphere, despite a high effective temperature of the star's atmosphere and the closeness of the planet to the star, is probably related to a low level of activity of the star. [ABSTRACT FROM AUTHOR]

Accretion luminosity of young star FU Ori (FUOR) increased from undetectable levels to hundreds of L⊙ in 1937 and remains nearly as high at the present time. In a recent paper, we showed how Extreme Evaporation (EE) of a young gas giant planet that migrated to a ∼10 d orbit around the star may power FUOR. However, our model assumed a power-law mass–radius relation for the evaporating planet. Here, we employ a stellar evolution code to model mass losing planets. We find that adiabatic planets expand rapidly, which results in runaway FUOR bursts. Superadiabatic planets contract while losing mass; their outbursts are dimming with time. Long steadily declining bursts such as FUOR require relatively fine-tuned internal planetary structure, which may be rare. More commonly we find that superadiabatic planets contract too rapidly and their EE falters, leading to FUOR burst stutter. This stutter allows a single planet to produce many short repeating bursts, which may be relevant to bursts observed in V346 Nor, V899, and V1647. We compute broad-band spectra of our best-fitting scenario for FUOR. Since the outburst is triggered behind the planet location, the mid-infrared (mid-IR) emission rises many months before the optical, similar to bursts in Gaia -17bpi and Gaia -18dvy. We show that in outbursts powered by the classic thermal instability, mid-IR lags the optical, whereas the dead zone activation models predict mid-IR light precede the optical burst by many years to decades. We comment on the stellar flyby scenario for FUOR. [ABSTRACT FROM AUTHOR]

Closely packed multiplanet systems are known to experience dynamical instability if the spacings between the planets are too small. Such instability can be tempered by the frictional forces acting on the planets from gaseous discs. A similar situation applies to stellar-mass black holes embedded in active galactic nuclei discs around supermassive black holes. We use N -body integrations to evaluate how the frictional damping of orbital eccentricity affects the growth of dynamical instability for a wide range of K (the difference in the planetary semimajor axes in units of the mutual Hill radius) and (unequal) planet masses. We find that, in general, the stable region (large K) and unstable region (small K) are separated by a "grey zone", where the (in)stability is not guaranteed. We report the numerical values of the critical spacing for stability K crit and the "grey zone" range in different systems, and provide fitting formulae for arbitrary frictional forcing strength. We show that the stability of a system depends on the damping time-scale τ relative to the zero-friction instability growth time-scale t inst: two-planet systems are stable if t inst ≳ τ; three-planet systems require t inst ≳ 10τ−100τ. When K is sufficiently small, t inst can be less than the synodic period between the planets, which makes frictional stabilization unlikely to occur. As K increases, t inst tends to grow exponentially, but can also fluctuate by a few orders of magnitude. We also devise a linear map to analyse the dynamical instability of the "planet + test mass" system, and find qualitative agreement with N -body simulations. [ABSTRACT FROM AUTHOR]

It has been suggested that small chemical anomalies observed in planet-hosting wide binary systems could be due to planet signatures, where the role of the planetary mass is still unknown. We search for a possible planet signature by analysing the T C trends in the remarkable binary system HD 196067–HD 196068. At the moment, only HD 196067 is known to host a planet that is near the brown dwarf regime. We take advantage of the strong physical similarity between both stars, which is crucial to achieving the highest possible precision in stellar parameters and elemental chemical abundances. This system gives us a unique opportunity to explore whether a possible depletion of refractories in a binary system could be inhibited by the presence of a massive planet. We performed a line-by-line chemical differential study, employing the non-solar-scaled opacities, in order to reach the highest precision in the calculations. After differentially comparing both stars, HD 196067 displays a clear deficiency in refractory elements in the T C plane, a lower iron content (0.051 dex), and also a lower Li  i content (0.14 dex) than its companion. In addition, the differential abundances reveal a T C trend. These targets represent the first cases of an abundance difference around a binary system hosting a super-Jupiter. Although we explored several scenarios to explain the chemical anomalies, none of them can be entirely ruled out. Additional monitoring of the system as well as studies of larger sample of wide binary systems hosting massive planets are needed to better understand the chemical abundance trend observed in HD 196067−68. [ABSTRACT FROM AUTHOR]

Ion sources are used in mass and energy spectrometry to ionize the neutral particles entering the instrument. The most classical technique used in planetary exploration is hot filaments emitting electrons with few tens of eV and impacting the neutral particles. The main limitations of such emitters are power consumption and outgassing due to heating of their local environment. Here, we built, tested, and demonstrated the advantages of using carbon nanotubes to replace hot filaments. Such emitters are based on a cold approach, use a limited amount of power, and achieve essentially the same efficiency as the hot filament-based source of ionization. [ABSTRACT FROM AUTHOR]

Alpha Centauri is a triple stellar system, and it contains the closest star to Earth (Proxima Centauri). Over the last decades, the stars in Alpha Cen and their orbits have been investigated in great detail. However, the possible scenarios for planet formation and evolution in this triple stellar system remain to be explored further. First, we present a 3D hydrodynamical simulation of the circumstellar discs in the binary Alpha Cen AB. Then, we compute stability maps for the planets within Alpha Cen obtained through N-body integrations. Last, we estimate the radial velocity (RV) signals of such planets. We find that the circumstellar discs within the binary cannot exceed 3 au in radius and that the available dust mass to form planets is about 30 M ⊕ . Planets around A and B are stable if their semimajor axes are below 3 au, while those around C are stable and remain unperturbed by the binary AB. For rocky planets, the planetary mass has only a mild effect on the stability. Therefore, Alpha Cen could have formed and hosted rocky planets around each star, which may be detected with RV methods in the future. The exoplanetary hunt in this triple stellar system must continue. [ABSTRACT FROM AUTHOR]

Magnetic reconnection is a fundamental mechanism for the transport of mass and energy in planetary magnetospheres and astrospheres. While the process of reconnection is itself ubiquitous across a multitude of systems, the techniques used for its analysis can vary across scientific disciplines. Here we frame the latest understanding of reconnection theory by missions such as NASA's Magnetospheric Multiscale (MMS) mission for use throughout the solar system and beyond. We discuss how reconnection can couple magnetized obstacles to both sub- and super-magnetosonic upstream flows. In addition, we address the need to model sheath plasmas and field-line draping around an obstacle to accurately parameterize the possibility for reconnection to occur. We conclude with a discussion of how reconnection energy conversion rates scale throughout the solar system. The results presented are not only applicable to within our solar system but also to astrospheres and exoplanets, such as the first recently detected exoplanet magnetosphere of HAT-11-1b. [ABSTRACT FROM AUTHOR]

We study tidal dissipation in models of rotating giant planets with masses in the range 0.1–10 M J throughout their evolution. Our models incorporate a frequency-dependent turbulent effective viscosity acting on equilibrium tides (including its modification by rapid rotation consistent with hydrodynamical simulations) and inertial waves in convection zones, and internal gravity waves in the thin radiative atmospheres. We consider a range of planetary evolutionary models for various masses and strengths of stellar instellation. Dissipation of inertial waves is computed using a frequency-averaged formalism fully accounting for planetary structures. Dissipation of gravity waves in the radiation zone is computed assuming these waves are launched adiabatically and are subsequently fully damped (by wave breaking/radiative damping). We compute modified tidal quality factors Q ′ and evolutionary time-scales for these planets as a function of their ages. We find inertial waves to be the dominant mechanism of tidal dissipation in giant planets whenever they are excited. Their excitation requires the tidal period (P tide) to be longer than half the planetary rotation (P rot/2), and we predict inertial waves to provide a typical Q ′ ∼ 103(P rot/1d)2, with values between 105 and 106 for a 10-d period. We show correlations of observed exoplanet eccentricities with tidal circularization time-scale predictions, highlighting the key role of planetary tides. A major uncertainty in planetary models is the role of stably-stratified layers resulting from compositional gradients, which we do not account for here, but which could modify predictions for tidal dissipation rates. [ABSTRACT FROM AUTHOR]

We extend the study of Papaloizou and Savonije of the tidal interactions of close orbiting giant planets with a central solar-type star to the situation where the spin axis of the central star and the orbital angular momentum are misaligned. We determine the tidal response taking into account the possibility of the excitation of r modes and the effect of tidal forcing due to potential perturbations that have zero frequency in a non-rotating frame. Although there is near resonance with r modes with degree l ′ = 1 and orders m  = ±1, half widths turn out to be sufficiently narrow so that in practice dissipation rates are found to be similar to those produced by non-resonant potential perturbations. We use our results to determine the evolution of the misalignment for the full range of initial inclination angles taking account of the spin-down of the central star due to magnetic braking. Overall we find the rate of tidal evolution to be unimportant for a one Jupiter mass planet with orbital period ∼3.7 d over a main-sequence lifetime. However, it becomes significant for higher mass planets and shorter orbital periods, approximately scaling as the square of the planet mass and the inverse fourth power of the orbital period. [ABSTRACT FROM AUTHOR]

Is the population of close-in planets orbiting M dwarfs sculpted by thermally driven escape or is it a direct outcome of the planet formation process? A number of recent empirical results strongly suggest the latter. However, the unique architecture of the TOI-1266 system presents a challenge to models of planet formation and atmospheric escape given its seemingly 'inverted' architecture of a large sub-Neptune (P b = 10.9 d, |$R_{p,b}=2.62\pm 0.11\, \mathrm{R}_{\oplus }$|⁠) orbiting interior to that of the system's smaller planet (P c = 18.8 d, |$R_{p,c}=2.13\pm 0.12\, \mathrm{R}_{\oplus }$|⁠). Here, we present revised planetary radii based on new TESS and diffuser-assisted ground-based transit observations, and characterize both planetary masses using a set of 145 radial velocity measurements from HARPS-N (⁠|$M_{p,b}=4.23\pm 0.69\, \mathrm{M}_{\oplus }, M_{p,c}=2.88\pm 0.80\, \mathrm{M}_{\oplus }$|⁠). Our analysis also reveals a third planet candidate (P d = 32.3 d, |$M_{p,d}\sin {i} = 4.59^{+0.96}_{-0.94}\, \mathrm{M}_{\oplus }$|⁠), which if real, would form a chain of near 5:3 period ratios, although the system is likely not in a mean motion resonance. Our results indicate that TOI-1266 b and c are among the lowest density sub-Neptunes around M dwarfs and likely exhibit distinct bulk compositions of a gas-enveloped terrestrial (X env,b = 5.5 ± 0.7 per cent) and a water-rich world (WMFc = 59 ± 14 per cent), which is supported by hydrodynamic escape models. If distinct bulk compositions are confirmed through atmospheric characterization, the system's unique architecture would represent an interesting test case of inside-out sub-Neptune formation at pebble traps. [ABSTRACT FROM AUTHOR]

The orbits of some warm Jupiters are highly inclined (20°–50°) to those of their exterior companions. Comparable misalignments are inferred between the outer and inner portions of some transition discs. These large inclinations may originate from planet–planet and planet–disc secular resonances that sweep across interplanetary space as parent discs disperse. The maximum factor by which a seed mutual inclination can be amplified is of the order of the square root of the angular momentum ratio of the resonant pair. We identify those giant planet systems (e.g. Kepler-448 and Kepler-693) that may have crossed a secular resonance, and estimate the required planet masses and semimajor axes in transition discs needed to warp their innermost portions (e.g. in CQ Tau). Passage through an inclination secular resonance could also explain the hypothesized large mutual inclinations in apsidally-orthogonal warm Jupiter systems (e.g. HD 147018). [ABSTRACT FROM AUTHOR]

We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of M★=0.1– 0.2 M⊙. In order to explore the optimal disk conditions for giant planet, we performed N-body simulations to investigate the growth and dynamical evolution of both single and multiple protoplanets in the disks with both inner viscously heated and outer stellar irradiated regions. The initial masses of the protoplanets are either assumed to be equal to 0.01 M⊕ or calculated based on the formula derived from streaming instability simulations. Our findings indicate that massive planets are more likely to form in disks with longer lifetimes, higher solid masses, moderate to high levels of disk turbulence, and larger initial masses of protoplanets. In the single protoplanet growth cases, the highest planet core mass that can be reached is generally lower than the threshold necessary to trigger rapid gas accretion, which impedes the formation of giant planets. Nonetheless, in multi-protoplanet cases, the cores can exceed the pebble isolation mass barrier aided by frequent planet–planet collisions. This consequently speeds their gas accretion up and promotes giant planet formation, making the optimal parameter space to grow giant planets substantially wider. Taken together, our results suggest that even around very-low-mass stellar hosts, the giant planets with orbital periods of ≲100 days are still likely to form when lunar-mass protoplanets first emerge from planetesimal accretion and then grow rapidly by a combination of pebble accretion and planet–planet collisions in disks with a high supply of a pebble reservoir >50 M⊕ and a turbulent level of αt ~ 10−3−10−2. [ABSTRACT FROM AUTHOR]

Context. A growing planet embedded in a protoplanetary disk induces three-dimensional gas flow, which exhibits a midplane outflow that can suppress dust accretion onto the planet and form global dust substructures (rings and gaps). Aims. Because analytic formulae for the planet-induced outflow are useful for modeling its influences on local and global dust surface densities and planet accretion, we derived analytic formulae that describe the morphology and velocity of the planet-induced outflow. Methods. We first performed three-dimensional, nonisothermal hydrodynamical simulations of the gas flow past a planet, which enabled us to introduce a fitting formula that describes the morphology of the outflow. We then derived an analytic formula for the outflow speed using Bernoulli's theorem. Results. We successfully derived a fitting formula for the midplane outflow morphology (the shape of the streamline), which is valid when the dimensionless thermal mass falls below m ≲ 0.6. The obtained analytic formulae for the outflow, such as the maximum outflow speed and the velocity distributions of the outflow in the radial and vertical directions to the disk, show good agreement with the numerical results. We find the following trends: (1) the maximum outflow speed increases with the planetary mass and has a peak of ~30–40% of the sound speed when the dimensionless thermal mass is m ~ 0.3, corresponding to a super-Earth mass planet at 1 au for the typical steady accretion disk model, and (2) the presence of the headwind (namely, the global pressure force acting in the positive radial direction of the disk) enhances (reduces) the outflow toward the outside (inside) of the planetary orbit. Conclusions. The planet-induced outflow of the gas affects the dust motion when the dimensionless stopping time of dust falls below St ≲ min(10 m2, 0.1), which can be used to model the dust velocity influenced by the outflow. [ABSTRACT FROM AUTHOR]

(Exo-)planets inherit their budget of chemical elements from a protoplanetary disc. The disc temperature determines the phase of each chemical species, which sets the composition of solids and gas available for planet formation. We investigate how gap structures, which are widely seen by recent disc observations, alter the thermal and chemical structure of a disc. Planet–disc interaction is a leading hypothesis of gap formation and so such changes could present a feedback that planets have on planet-forming material. Both the planet gap-opening process and the disc thermal structure are well studied individually, but how the gap-opening process affects disc thermal structure evolution remains an open question. We develop a new modelling method by iterating hydrodynamical and radiative transfer simulations to explore the gap-opening feedback on disc thermal structure. We carry out parameter studies by considering different planet locations r p and planet masses M p. We find that for the same r p and M p, our iteration method predicts a wider and deeper gap than the non-iteration method. We also find that the inner disc and gap temperature from the iteration method can vary strongly from the non-iteration or disc without planets, which can further influence dust-trap conditions, iceline locations, and distribution of various ices, such as H2O, CO2, and CO on large dust grains ('pebbles'). Through that, a gap-opening planet can complicate the canonical picture of the non-planet disc C/O ratio and influence the composition of the next generation of planetesimals and planets. [ABSTRACT FROM AUTHOR]

We conduct a survey, which explores the data releases of the European Space Agency (ESA)– Gaia mission, in order to investigate the multiplicity of exoplanet hosts at distances of less than 625 pc around the Sun. With the accurate Gaia astrometry we are able to detect stellar and substellar companions of exoplanet hosts by proving the equidistance and common proper motion of these objects. Furthermore, by using the astro- and photometric data provided by the ESA– Gaia mission, we characterize the nature of the identified companions (substellar, stellar, main-sequence, or evolved), determine their properties (mass, effective temperature, and projected separation to the associated exoplanet host), and verify their orbital stability. In addition to main-sequence stars, the companions detected in this study include several brown and white dwarfs. So far in the course of our survey, the multiplicity of more than 2200 exoplanet hosts could be investigated, yielding a multiplicity rate of about 16 per cent (increased to about 19 per cent including published detections from other surveys). Finally, the derived physical properties of the companions were used to investigate the impact of the stellar multiplicity on the properties of the exoplanets and their hosts. In general, there are significant differences in the properties of these objects, dependent on the multiplicity status of their host system, e.g. higher masses of both planets and exoplanet hosts in multiple star systems. Furthermore, the masses and orbital eccentricities of multiple star planets significantly depend on the gravitational impact, induced by the companion star of the exoplanet host. [ABSTRACT FROM AUTHOR]

Hot Jupiters, a special class of exoplanets, always draw attention due to their intriguing characteristics. In this paper, we have continued our endeavor to understand the distribution of hot Jupiter populations and the architecture of planetary systems through the statistical framework. Different techniques to discover hot Jupiters have been studied here, and current data suggested that the transit method has better chances of discovering light and shortperiod candidates. Relation between orbital eccentricity and other planetary parameters like mass and orbital periods have been investigated to support the existence of a discontinuity in planetary mass distribution at ~4 MJ. A low p-value in the KS test indicates the existence of two different populations of hot Jupiters having a possibly different channel of formation. We also discussed these statistical results' theoretical and empirical implications for dynamical evolution. [ABSTRACT FROM AUTHOR]

Planets orbiting young stars are thought to experience atmospheric evaporation as a result of the host stars' high-magnetic activity. We study the evaporation history and expected future of the three known transiting exoplanets in the young multiplanet system K2-198. Based on spectroscopic and photometric measurements, we estimate an age of the K-dwarf host star between 200 and 500 Myr, and calculate the high-energy environment of these planets using eROSITA X-ray measurements. We find that the innermost planet K2-198c has likely lost its primordial envelope within the first few 10s of Myr regardless of the age at which the star drops out of the saturated X-ray regime. For the two outer planets, a range of initial envelope mass fractions is possible, depending on the not-yet-measured planetary mass and the stars' spin-down history. Regarding the future of the system, we find that the outermost planet K2-198b is stable against photoevaporation for a wide range of planetary masses, while the middle planet K2-198d is only able to retain an atmosphere for a mass range between ∼7 and 18 M⊕. Lower mass planets are too susceptible to mass-loss, and a very thin present-day envelope for higher mass planets is easily lost with the estimated mass-loss rates. Our results support the idea that all three planets started out above the radius valley in the (sub-)Neptune regime and were then transformed into their current states by atmospheric evaporation, but also stress the importance of measuring planetary masses for (young) multiplanet systems before conducting more detailed photoevaporation simulations. [ABSTRACT FROM AUTHOR]

This work combines spectroscopic and photometric data of the polluted white dwarf WD 0141−675, which has a now retracted astrometric super-Jupiter candidate, and investigates the most promising ways to confirm Gaia astrometric planetary candidates and obtain follow-up data. Obtaining precise radial velocity measurements for white dwarfs is challenging due to their intrinsic faint magnitudes, lack of spectral absorption lines, and broad spectral features. However, dedicated radial velocity campaigns are capable of confirming close-in giant exoplanets (a few M Jup) around polluted white dwarfs, where additional metal lines aid radial velocity measurements. Infrared emission from these giant exoplanets is shown to be detectable with JWST Mid-Infrared Instrument (MIRI) and will provide constraints on the formation of the planet. Using the initial Gaia astrometric solution for WD 0141−675 as a case study, if there were a planet with a 33.65 d period or less with a nearly edge-on orbit, (1) ground-based radial velocity monitoring limits the mass to <15.4  M Jup, and (2) space-based infrared photometry shows a lack of infrared excess and in a cloud-free planetary cooling scenario, a substellar companion would have to be <16  M Jup and be older than 3.7 Gyr. These results demonstrate how radial velocities and infrared photometry can probe the mass of the objects producing some of the astrometric signals, and rule out parts of the brown dwarf and planet mass parameter space. Therefore, combining astrometric data with spectroscopic and photometric data is crucial to both confirm and characterize astrometric planet candidates around white dwarfs. [ABSTRACT FROM AUTHOR]

Transit timing variations (TTVs) can be induced by a range of physical phenomena, including planet–planet interactions, planet–moon interactions, and stellar activity. Recent work has shown that roughly half of moons would induce fast TTVs with a short period in the range of 2–4 orbits of its host planet around the star. An investigation of the Kepler TTV data in this period range identified one primary target of interest, Kepler-1513 b. Kepler-1513 b is a |$8.05^{+0.58}_{-0.40}$| R⊕ planet orbiting a late G-type dwarf at |$0.53^{+0.04}_{-0.03}$| au. Using Kepler photometry, this initial analysis showed that Kepler-1513 b's TTVs were consistent with a moon. Here, we report photometric observations of two additional transits nearly a decade after the last Kepler transit using both ground-based observations and space-based photometry with TESS. These new transit observations introduce a previously undetected long period TTV, in addition to the original short period TTV signal. Using the complete transit data set, we investigate whether a non-transiting planet, a moon, or stellar activity could induce the observed TTVs. We find that only a non-transiting perturbing planet can reproduce the observed TTVs. We additionally perform transit origami on the Kepler photometry, which independently applies pressure against a moon hypothesis. Specifically, we find that Kepler-1513 b's TTVs are consistent with an exterior non-transiting ∼Saturn mass planet, Kepler-1513 c, on a wide orbit, |$\sim 5~{{\ \rm per \, cent}}$| outside a 5:1 period ratio with Kepler-1513 b. This example introduces a previously unidentified cause for planetary interlopers in the exomoon corridor, namely an insufficient baseline of observations. [ABSTRACT FROM AUTHOR]